FOAF Wiki - User contributions [en]

FoafProject

2007-11-01T01:58:02Z

Admin: cleaned up 1st parag a bit, linked openid piece from DIG group

This is the Wiki site for the [http://wiki.foaf-project.org/ FOAF project].

Feel free to add links, suggestions here, much as you might on the foaf-dev mailing list. Leave a link and brief description here if you add new content. A consequence of this is that as a reader, you shouldn't expect complete coherence from the site: you'll find a mix of useful tips, personal content, brainstorming and scribbles. Consider this a freeform scratchpad, designed to be easy to update, and as a quick place to capture an idea or link before it is forgotten.

This wiki is terribly messy; sorry! As of Nov 1st 2007 it is republished using MediaWiki with better spam control.

= Editing pages =

We got spammed to bits; the Wiki has been migrated to MediaWiki, and we prefer edits associated with an OpenID. In the future (as spammers make more use of OpenID) we are likely to require some form of connection to a known member of the community before edits are accepted. For work in this area see the [http://dig.csail.mit.edu/breadcrumbs/node/206 writeup] from the MIT DIG group on using FOAF and OpenID together.

= Jumping Off Points =

Some starting points:

* The '''[[FAQ]]''' has answers to a number of FOAF related questions including general project and "getting started" information. See [[FoafHistory]] for some background on the origins of the FOAF project, and FoafMentions for links to FOAF in the news (From the days when it was notable for FOAF to be mentioned elsewhere!)
* upcoming and past '''[[FoafMeet]]'''s - face to face FOAF meetings
* Information for '''[[Developers]]'''
* '''[[Tools]]''', including FoafNaut and other CoolStuff
* '''[[DataSources]]''' - various places to get FOAF data, including sites that export it
* '''[[Vocabulary]]''' -- information about FOAF syntax and vocabulary, see also FoafExamples which has a number of worked examples showing how to use particular aspects of the FOAF vocabulary
* '''[[Tutorials]]''' -- a list of FOAF tutorials out on the web. Also check out CategoryTutorial
* The '''[[FOAFBulletinBoard]]''' provides a way for sharing your FOAF URL with other people, and more importantly Foaf harvesters
* '''[[ApplicationIdeas]]''' -- a page listing ideas for FOAF applications.
* '''[[Criticism]]''' -- critiques of FOAF

See also RecentChanges for machine-generated list of latest edits and additions, and ChangeLog for some manual entries.

= Active Pages =

A Wiki really comes into its own when its users help to refine each others pages, e.g. adding information, answering questions, providing feedback, etc. Here's a list of pages that you can help out with. * [[Comments]] -- pages requesting comments. Add your feedback
* [[TODO]] -- pages requesting help. Give them some love.
* UnderConstruction -- pages under construction. Give the author time to finish before adding comments.
* [[Refactoring]] -- pages being reworked. Let things settle down before editing.
* [[WantedPages]] -- pages that are awaiting creation. Add some content
* [[OrphanedPages]] -- pages that aren't linked into the Wiki. Delete them if they're dead, or link 'em if they're useful
* [[AbandonedPages]] -- old, unedited pages. Bring them up to date.
= Misc =

Some related resources both here and elsewhere on the web. Some of this content will shortly move off the home page.
* [[MetadataVIATEC]]
* FoafAuthentication
* FoafCorp.
* ConnectingUsenetWithFoaf discusses the use of FOAF in discussion newsgroups.
* [[TowardFOAFster]] -- an [http://www.intertwingly.net/wiki/pie/FrontPage Atom]-style effort to specify FOAF extensions to facilitate online matchmaking
* CoDepiction -- a dropoff point for images worthy of cataloguing
* SpaceNamespace -- Geo-mapping work
* AccessiblePlanet -- danbri and william loughborough project notes
* [[RDFWebSiteDesign]] notes
* [http://www15.brinkster.com/semaview/default.aspx] View an interesting application of the semantic web which brings together an Office XP addin to publish your contacts in RDF format to a webservice which then forms communities based on your friends. You can also browse your communities in the associated web page.
* [http://www15.brinkster.com/semaview/foaf.aspx] A simple FOAF generator, comments are welcome.
* FoafIdeas
* ExpertFinder -- Joint Initiative on Extending the FOAF Vocabulary for Expert Finding
* [[FOAFnet.org]]
* [http://www-900.ibm.com/developerWorks/cn/xml/x-watch/part3/index.shtml Foaf Introduction (Chinese)]

* FoafProjectHomepageNotes; http://beta.foaf-project.org/ - beta website.

= Elsewhere =

Related sites

* The [ESW:FrontPage ESW Wiki] may also be of some interest, being full of notes on RDF and Semantic Web technology.
----

Web site / wiki contact: DanBri (danbri@rdfweb.org) or the FOAF mailing list, rdfweb-dev@vapours.rdfweb.org

[[Category:Main]]

Main Page

2007-11-01T01:52:30Z

Admin:

<big>'''MediaWiki has been successfully installed.'''</big>

Consult the [http://meta.wikimedia.org/wiki/Help:Contents User's Guide] for information on using the wiki software.

OK this edit made by danbri ... via openid.

== Getting started ==

* [http://www.mediawiki.org/wiki/Help:Configuration_settings Configuration settings list]
* [http://www.mediawiki.org/wiki/Help:FAQ MediaWiki FAQ]
* [http://mail.wikimedia.org/mailman/listinfo/mediawiki-announce MediaWiki release mailing list]

== Raw category list ==

The 320 pages imported from old Wiki are in the following categories:

* [[Category:Main]]
* [[Category:Vocabulary]] ([[Category:Vocabulary_Issues]], [[Category:Vocabulary_OtherVocabs]], [[Category:Vocabulary_UsageGuidelines]]).
* [[Category:Adaptors]], [[Category:Applications]], [[Category:TechAndSoftware]]
* [[Category:Events]] ([[Category:Events_FoafCamp]], [[Category:Events_FoafGalway]], [[Category:Events_FoafMeets]] ...)
* [[Category:People]]
* [[Category:ExpertFinder]]
* [[Category:FOAFWebsite]]
* [[Category:Other]]
* [[Category:Offtopic]]

Todo: make this more readable... and hmm how does one LINK to a category without claiming the page is IN that category?

Main Page

2007-11-01T01:50:49Z

Admin: listing categories we imported

Using Relationship vocabulary

2007-11-01T01:43:23Z

Admin: Automated import of articles

= FOAF relationship module =

[http://vocab.org/relationship/ A module] for defining relationships in FOAF by EricVitiello.

On [[Date(2004-05-04T16:59:30Z)]], includes properties: <pre>friendOf</pre>, <pre>acquaintanceOf</pre>, <pre>parentOf</pre>, <pre>siblingOf</pre>, <pre>childOf</pre>, <pre>grandchildOf</pre>, <pre>spouseOf</pre>, <pre>enemyOf</pre>, <pre>antagonistOf</pre>, <pre>ambivalentOf</pre>, <pre>lostContactWith</pre>, <pre>knowsOf</pre>, <pre>wouldLikeToKnow</pre>, <pre>knowsInPassing</pre>, <pre>knowsByReputation</pre>, <pre>closeFriendOf</pre>, <pre>hasMet</pre>, <pre>worksWith</pre>, <pre>colleagueOf</pre>, <pre>collaboratesWith</pre>, <pre>employerOf</pre>, <pre>employedBy</pre>, <pre>mentorOf</pre>, <pre>apprenticeTo</pre>, <pre>livesWith</pre>, <pre>neighborOf</pre>, <pre>grandparentOf</pre>, <pre>lifePartnerOf</pre>, <pre>engagedTo</pre>, <pre>ancestorOf</pre>, <pre>descendantOf</pre>, <pre>participantIn</pre>, <pre>participant</pre>

== Proposed Additions ==

There is a [http://rdfweb.org/pipermail/rdfweb-dev/2003-December/012257.html suggestion on the table]
by EricSigler to add a memberOf property to the Relationships vocabulary to allow better workings with
the foaf:Group property.

* IssueTracker entry MemberVocabIssue
* [http://esigler.2nw.net/blog/2003/12/30/foaf_and_groups Proposal plus examples]

<pre>

<foaf:Person rdf:nodeID="me">
<foaf:blah>...</foaf:blah>
<foaf:memberOf rdf:resource="http://example.com/groupfile.rdf#spelunkers" />
</foaf:Person>
<foaf:Group rdf:nodeID="spelunkers">
<rdfs:seeAlso rdf:resource="http://example.com/groupfile.rdf" />
<foaf:member rdf:nodeID="me" />
</foaf:Group>

</pre>
[[Category:Vocabulary_UsageGuidelines]]

UsingFoafWeblog

2007-11-01T01:43:11Z

Admin: Automated import of articles

The FoafVocab includes a property 'foaf:weblog' which relates an Agent to a document that is their weblog.

Here is some example markup showing how to describe someone and their weblog (taken from Joshua's [http://www.netcrucible.com/blog/msft.xml XML listing of Microsoft bloggers]).

<pre>
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:dc="http://purl.org/dc/elements/1.1/">

<foaf:Person>
<foaf:name>Joshua Allen</foaf:name>
<foaf:workplaceHomepage rdf:resource="http://www.microsoft.com/"/>
<foaf:weblog
dc:title="Better Living Through Software"
dc:description=" Life at Microsoft, the software industry from a rational perspective"
rdf:resource="http://www.netcrucible.com/blog/"/>
<rdfs:seeAlso rdf:resource="http://www.netcrucible.com/blog/rss.xml"/>

</foaf:Person>

</rdf:RDF>

</pre>

Since this is RDF, it could be decorated with further information, eg. an rdfs:seeAlso to a FOAF file for the blogger, etc. Here we show the use of the foaf:workplaceHomepage property which relates a Person to the homepage of somewhere they work.

Here is a graph of the data structure encoded in the RDF/XML markup shown above. It was generated using W3C's online parser, validator and visualisation [http://www.w3.org/RDF/Validator/ service], and reveals the underlying "entities and relationships" graph structure that RDF uses. You can see nodes in the diagram that correspond to the things we're describing: Joshua, his Blog, and the homepage of a place he works.

http://rdfweb.org/images/foaf/foafweblog-ms-joshua.png

'''Generating the FOAF using XSLT'''

Here's a simple [http://www.ldodds.com/foaf/misc/ms-bloggers2foaf.xsl XSLT stylesheet] that takes the [http://www.netcrucible.com/blog/msft.xml XML listing of Microsoft bloggers] and converts it into [http://www.ldodds.com/foaf/misc/ms-bloggers.rdf a FOAF document].

At the time of writing there's a slight issue with processing the XML listing as the encoding seems to be incorrect (should be iso-8859-1). If that were corrected then we could could [http://www.w3.org/2000/06/webdata/xslt?xslfile=http://www.ldodds.com/foaf/misc/ms-bloggers2foaf.xsl&xmlfile=http://www.netcrucible.com/blog/msft.xml perform the conversion automatically].
[[Category:Vocabulary_UsageGuidelines]]

UsingFoafTopic

2007-11-01T01:42:59Z

Admin: Automated import of articles

= Using foaf:topic =

Using foaf:topic to relate a page to one of the topics of that page

Example: saying that a page is about the company "mcdonalds":

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:fc="http://xmlns.com/foaf/corp#"
xmlns:dc="http://purl.org/dc/elements/1.1/" >

<foaf:Document rdf:about="http://c2.com/cgi/wiki?McDonalds">
<dc:title>McDonalds</dc:title>
<dc:description>McDonalds page on the C2 Wiki</dc:description>
<foaf:topic>
<fc:Company>
<fc:name>McDonalds</fc:name>
<foaf:homepage rdf:resource="http://www.mcdonalds.com/"/>
</fc:Company>
</foaf:topic>
</foaf:Document>
</rdf:RDF>
</pre>

''Q: That seems to be a document-centric approach. How would this look if I wanted to
put the web page information inside the elements describing the company?''

''A: From the point of view of the abstract RDF graph, the way you nest the XML elements doesn't really matter. However in practice there are interactions between the way a relationship is named ('depicts' versus 'depiction', for eg) and the way
the markup is written.''

For example, we can re-order the above XML to be neither company-centric nor
document-centric:

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:fc="http://xmlns.com/foaf/corp#"
xmlns:dc="http://purl.org/dc/elements/1.1/" >

<fc:Company rdf:nodeID="mcd">
<fc:name>McDonalds</fc:name>
<foaf:homepage rdf:resource="http://www.mcdonalds.com/"/>
</fc:Company>

<foaf:Document rdf:about="http://c2.com/cgi/wiki?McDonalds">
<dc:title>McDonalds</dc:title>
<dc:description>McDonalds page on the C2 Wiki</dc:description>
<foaf:topic rdf:nodeID="mcd"/>
</foaf:Document>

</rdf:RDF>
</pre>

Note that the 'topic' relation always points from a document to a company. This makes it
hard to put the document description ''inside'' the company description.

In some cases, RDF vocabularies include 'inverse properties' that say the same thing
backwards. In FOAF for example, we have foaf:depicts and foaf:depiction, as well as
foaf:topic and foaf:page. Here we show the use of foaf:page to relate the company to a
page that is about it:

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:fc="http://xmlns.com/foaf/corp#"
xmlns:dc="http://purl.org/dc/elements/1.1/" >

<fc:Company>
<fc:name>McDonalds</fc:name>
<foaf:homepage rdf:resource="http://www.mcdonalds.com/"/>
<foaf:page>
<foaf:Document rdf:about="http://c2.com/cgi/wiki?McDonalds">
<dc:title>McDonalds</dc:title>
<dc:description>McDonalds page on the C2 Wiki</dc:description>
</foaf:Document>
</foaf:page>
</fc:Company>

</rdf:RDF>

</pre>

As you can see, foaf:page is a bit like foaf:homepage, except that anyone can make a foaf:page about
something, whereas the notion of a foaf:homepage is associated with notions of authority: I can't create
the homepage for someone else's company.

This is a bit redundant, since foaf:topic and foaf:page express the same information, but can nevertheless be useful if you care about the XML form of your RDF data.
----
CategoryTutorial
[[Category:Vocabulary_UsageGuidelines]]

UsingFoafTipjar

2007-11-01T01:42:44Z

Admin: Automated import of articles

This page serves as a hub of references to further document development of the '''foaf:tipjar''' property.

* [http://rdfweb.org/mt/foaflog/archives/2004/02/12/20.07.32/index.html FOAFLog Discussion of foaf:tipjar].
* [http://kasei.us/archives/2004/02/12/tipjar Suggestion of integrating foaf:tipjar in ID3 tags].

Recent comments from MikeLinksvayer of [http://creativecommons.org Creative Commons]:

<pre>

Date: Mon, 05 Apr 2004 21:39:07 -0700
From: Mike Linksvayer <ml at creativecommons.org>
To: "B.K. DeLong" <bkdelong@pobox.com>
Subject: Re: foaf:tipjar ?

I just noticed the other day <http://rdfweb.org/topic/UsingDublinCoreCreator>,
which runs counter to the way I was planning to implement foaf:Agent
(and thus foaf:tipjar) within CC metadata, like

<cc:Work>
<dc:creator>
<foaf:Person>
<foaf:name>John Doe</foaf:name>
<foaf:homepage rdf:resource="http://example.com/~jd/"/>
<foaf:tipjar rdf:resource="http://example.com/~jd/fund-me"/>
</foaf:Person>
</dc:creator>
</cc:Work>

a usage the above page tentatively recommends against.

This seems like a really natural usage. Note that an example under discussion at
dc-agents uses such a construction, if I understand it (example 2 at
http://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0402&L=dc-agents&P=703)
Yes, dc:creator can be messy. But if we have to rely on something ad hoc like

?D dc:creator ?N .
implied by
?D foaf:maker ?M .
?M foaf:name ?N

why not

?D dc:creator ?N
implied by
?D dc:creator ?M .
?M foaf:name ?N

Perhaps because we theoretically also have to deal with any arbitrary RDF construct in dc:creator.

I'm not complaining here, just wondering aloud what CC should do --

(1) Recommend foaf:maker to denote creator of a copyrightable work
(2) Use the advised-against construct mixing dc:creator and foaf:Agent above
(3) Wait to see what the re-opened(?) dc-agents group comes up with
(see jiscmail link above). Note that at least two people posted public responses
saying "look at FOAF" in response to the dc-agents requirements posting, as I,
and I bet others, did privately.

(3) doesn't seem to be a realistic option for CC, as we're probably going to do
something with tipjars in the next couple months, and it would be good to have
the appropriate metadata ready. FWIW we may also do something along the lines
of "here's where you can buy out the rights that have been reserved."

</pre>
[[Category:Vocabulary_UsageGuidelines]]

UsingFoafKnows

2007-11-01T01:42:32Z

Admin: Automated import of articles

= Using foaf:knows to relate people together =

The "friend of a friend" aspect of FOAF arises from the ability to say that one Person "knows" another Person. "knows" is used in a deliberately vague sense here that includes "is friends with", "corresponds with", etc. Additional elaborations on the basic FOAF data can further clarify these relationships.

<pre>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:Person>
<foaf:name>Leigh Dodds</foaf:name>
<foaf:firstName>Leigh</foaf:firstName>
<foaf:surname>Dodds</foaf:surname>
<foaf:mbox_sha1sum>71b88e951cb5f07518d69e5bb49a45100fbc3ca5</foaf:mbox_sha1sum>
<foaf:knows>
<foaf:Person>
<foaf:name>Dan Brickley</foaf:name>
<foaf:mbox_sha1sum>241021fb0e6289f92815fc210f9e9137262c252e</foaf:mbox_sha1sum>
<rdfs:seeAlso
rdf:resource="http://rdfweb.org/people/danbri/foaf.rdf"/>
</foaf:Person>
</foaf:knows>
</foaf:Person>
</rdf:RDF>
<--
-->
</pre>

Which says "there is a person called Leigh Dodds with a mailbox whose hashed value is..., who knows a person called Dan Brickley whose mailbox is..., and that Dan Brickley is further described in foaf.rdf"

== Cross Referencing ==

The foaf:knows relationship can also be stated by cross-referencing within the file. The following is equivalent to the above example:

<pre>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:Person>
<foaf:name>Leigh Dodds</foaf:name>
<foaf:firstName>Leigh</foaf:firstName>
<foaf:surname>Dodds</foaf:surname>
<foaf:mbox_sha1sum>71b88e951cb5f07518d69e5bb49a45100fbc3ca5</foaf:mbox_sha1sum>
<foaf:knows rdf:resource="#dan">
</foaf:Person>

<foaf:Person rdf:ID="dan">
<foaf:name>Dan Brickley</foaf:name>
<foaf:mbox_sha1sum>241021fb0e6289f92815fc210f9e9137262c252e</foaf:mbox_sha1sum>
<rdfs:seeAlso
rdf:resource="http://rdfweb.org/people/danbri/foaf.rdf"/>
</foaf:Person>
</rdf:RDF>
</pre>

It should be clear from the above example that a single FOAF document can describe multiple people. There's no concept of a "primary" person in the document upon which all properties or relationships are based.
----
CategoryTutorial
[[Category:Vocabulary_UsageGuidelines]]

UsingFoafImage

2007-11-01T01:42:22Z

Admin: Automated import of articles

= Associating Images with People (and other resources) =

Another way of [[DescribingAPerson]] is with an image. Here's how to associate a Person with an image in a FOAF document.

<pre>
<foaf:Image/> 
</pre>

<pre>
<foaf:Image rdf:about="http://rdfweb.org/people/danbri/mugshot/danbri-small.jpeg"/>


<foaf:Person rdf:nodeID="person1"><foaf:name>Dan Brickley</foaf:name></foaf:Person>

</pre>

<pre>
<foaf:Person rdf:nodeID="person1">
<foaf:depiction rdf:resource="http://rdfweb.org/people/danbri/mugshot/danbri-small.jpeg"/>
</foaf:Person>

</pre>

<pre>
<foaf:Person>
<foaf:name>Dan Brickley</foaf:name>
<foaf:depiction>
<foaf:Image/>
</foaf:depiction>
</foaf:Person>

</pre>

<pre>
<foaf:Person>
<foaf:name>Dan Brickley</foaf:name>
<foaf:depiction>
<foaf:Image>
<foaf:sha1>7eff189e90a0b21cddb1b490ee39524f3cd2ca3e</foaf:sha1>
</foaf:Image>
</foaf:depiction>
</foaf:Person>

</pre>

This gives us the raw materials to say that there is a person that is depicted by an image
which has such'n'so URI name, and such'n'so content (assured by hashing to get a unique(ish) fingerprint).
This could be the raw materials needed to reproduce [http://rdfweb.org/people/danbri/2001/02/semanticweb-and-me/ passport-like functionality in the Semantic Web].

<pre>
<foaf:Person>
<foaf:name>Dan Brickley</foaf:name>
<foaf:depiction>
<foaf:Image rdf:about="http://rdfweb.org/people/danbri/mugshot/danbri-small.jpeg">
<foaf:sha1>7eff189e90a0b21cddb1b490ee39524f3cd2ca3e</foaf:sha1>
</foaf:Image>
</foaf:depiction>
</foaf:Person>

</pre>

But assuming someone writes RDF making the claim that I like look the contents of (some version of) some picture, how can the author of that document assure us it hasn't been altered, changed? (see [http://usefulinc.com/foaf/signingFoafFiles foafbot docs on PGP signed RDF/XML]).
----
CategoryTutorial
[[Category:Vocabulary_UsageGuidelines]]

UsingDublinCoreCreator

2007-11-01T01:42:10Z

Admin: Automated import of articles

The [http://www.dublincore.org/ Dublin Core Metadata Initiative] define a property, dc:creator which can be used in RDF data.

Here we explore some ways it can be mixed with other RDF data such as FOAF, and through doing so highlight a well-known problem.

(first draft by danbri, July 2003)

''It isn't clear whether dc:creator relates documents to people, or to their names''.

For historical reasons, DC has had a concern with 'dumbing down', to allow simple and complex metadata to co-exist.

Some DC RDF looks like this:

<pre>
<rdf:Description>
<dc:title>My document...</dc:title>
<dc:creator>Dan Brickley</dc:creator>
<dc:description>A textual abstract could go here</dc:description>
</rdf:Description>
</pre>

In fact, the [http://dublincore.org/documents/dcmes-xml/ Simple DC in RDF document] encourages just this style.

However, it is also quite common to see dc:creator used as a relationship to a Person. For example:

<pre>
<rdf:Description>
<dc:title>My document...</dc:title>
<dc:creator>
<foaf:Person>
<foaf:name>Dan Brickley</foaf:name>
<foaf:homepage rdf:resource="http://rdfweb.org/people/danbri/"/>
</foaf:Person>
<dc:description>A textual abstract could go here</dc:description>
</rdf:Description>
</pre>

Currently a fair amount of FOAF data takes this approach. We have our own fairly rich way of describing people, but we try to use Dublin Core's 'creator' property to relate people to documents. We use DC to describe documents, of course; that's what it is particularly good for.

OK, so what do the specs say? Time for a trip down memory lane...

Those who have not participated in Dublin Core should, first of all, know that the specs have changed a bit.

One thing about DC: there are generic specs defining the properties, and then specs defining their representation in RDF/XML (and also non-RDF XML).

The first spec for DC-in-RDF we had out was this one:

* [http://www.ukoln.ac.uk/metadata/resources/dc/datamodel/WD-dc-rdf/ Guidance on expressing the Dublin Core within the Resource Description Framework (RDF)] (Paul Miller, Eric Miller, Dan Brickley).

But this has been considered obsolete since ~2000. If you look at it, you'll see a pretty complex attempt at allowing DC to be extended, yet for all DC applications to know enough about the extensions to at least retrieve a textual value for 'creator'.
Note that my second example above fails at this aim, since there is no way that a non-FOAF-aware tool could realise that the
string 'Dan Brickley' was the name of the creator. Many many many Dublin Core discussions centred around different ways of achieving such extensibility.

A more mature DC in RDF spec:

* [http://dublincore.org/documents/2002/07/31/dcmes-xml/ Expressing Simple Dublin Core in RDF/XML] (Dave Beckett, Eric Miller, Dan Brickley)

This only deals with using the 15 DC properties as simple textually-valued properties, as in the first example above.

The holy grail of Dublin Core, of course, was the seamless extension of this to 'qualified' Dublin Core.

Here is the latest qualified DC / RDF spec:

* [http://dublincore.org/documents/2002/04/14/dcq-rdf-xml/ Expressing Qualified Dublin Core in RDF / XML] (Stefan Kokkelink, Roland Schw�nzl)

A strength of this spec is that it tries to use RDF's native facilities wherever possible. But that is also unfortunately one of its weaknesses: it makes things more complicated by using bits of RDF that (to be honest) are best ignored.

For example:

<pre>
<rdf:Description dc:title="Healthy Meat">
<dc:creator>
<rdf:Bag>
<rdf:li>Jon Doe</rdf:li>
<rdf:li>Karin Mustermann</rdf:li>
</rdf:Bag>
</dc:creator>
</rdf:Description>
</pre>

This uses RDF's notion of a Bag, ie an unordered list. The spec also shows the use of rdf:Seq (an ordered list) and rdf:Alt (alternates).

Our investigation began by wondering whether we should use dc:creator as a relationship between a document and a person, or just as a relationship between a document and that person's name. Looking at this latest DC-in-RDF spec, things get more complex. We are being encouraged to also, sometimes, use dc:creator as a relation between a document and ... another datastructure (list of some kind).

This, to be blunt, is a ''pain in the butt'' for implementors. When you meet a dc:creator property, what on earth is it referencing?:

* a name of a person?
* a person (who may have arbitrary other properties you understand, or don't understand)
* a list (alt, seq, bag) of names?
* a list (alt, seq, bag) of persons...?

And that's without going into the particular uselessness of RDF's Alt construct (short version: it borders meaningless) or Bag (short version: just use repeated properties, simpler and clearer).

There is actually a [http://dublincore.org/documents/2002/04/14/dcq-rdf-xml/#sec3 lot more] in the dcq-rdf-xml document, including a 'dumb down' algorithm for trying to pull out relevant simple strings from the nearby regions of the RDF graph.

Here is an example it gives, showing a vcard-in-rdf vocab mixed with DC:
<pre>
<rdf:RDF xmlns:rdf = "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:vCard = "http://www.w3.org/2001/vcard-rdf/3.0#">
<rdf:Description>
<dc:creator>
<rdf:Description rdf:about = "http://qqqfoo.com/staff/corky" >
<rdfs:label> Corky Crystal </rdfs:label>
<vCard:FN> Corky Crystal </vCard:FN>
<vCard:N rdf:parseType="Resource">
<vCard:Family> Crystal </vCard:Family>
<vCard:Given> Corky </vCard:Given>
<vCard:Other> Jacky </vCard:Other>
<vCard:Prefix> Dr </vCard:Prefix>
</vCard:N>
<vCard:BDAY> 1980-01-01 </vCard:BDAY>
</rdf:Description>
</dc:creator>
</rdf:Description>
</rdf:RDF>
</pre>

See the above spec for the details of their dumb-down algorithm.

There are lots of ways dc:creator is being used. This makes it hard to know, given some document, what it's DC creator is. How can it be true that both I ''and my name'' are dc:creator of the same thing? We're in a bit of a mess.

Let's go back and look at the core definition of dc:creator...

From feeding 'http://purl.org/dc/elements/1.1/creator' to the Web, I get the following definition back:
<pre>
<rdf:Property rdf:about="http://purl.org/dc/elements/1.1/creator">
<rdfs:label xml:lang="en-US">Creator</rdfs:label>
<rdfs:comment xml:lang="en-US">An entity primarily responsible for making the content
of the resource.</rdfs:comment>
<dc:description xml:lang="en-US">Examples of a Creator include a person, an organisation,
or a service. Typically, the name of a Creator should
be used to indicate the entity.</dc:description>
<rdfs:isDefinedBy rdf:resource="http://purl.org/dc/elements/1.1/"/>
<dcterms:issued>1999-07-02</dcterms:issued>
<dcterms:modified>2002-10-04</dcterms:modified>
<dc:type rdf:resource="http://dublincore.org/usage/documents/principles/#element"/>
<dcterms:hasVersion rdf:resource="http://dublincore.org/usage/terms/history/#creator-004"/>
</rdf:Property>
</pre>

This is the formal definition of dc:creator. And the core problem is quite clear: we are trying to have it both ways.

We say 'an entity primarily responsible...', which sets the expectation that the dc:creator of something is a thing that creeated it.

But we also say, 'Typically the name of a creator should be used to indicate the entity.', which sets the expectation that the dc:creator of something will be a name of its creator.

Now the problem is that RDF is quite happy with doing either, but it makes the difference painfully obvious. And so we are left with a world in which some people write:
<pre>
<dc:creator>Dan Brickley</dc:creator>
</pre>
...while others write:
<pre>
<dc:creator>
<Person>
<name>Dan Brickley</name>
</Person>
</dc:creator>
</pre>

So, what to do?

At the moment, we have a number of FOAF examples which encourage the latter use. This is because it seemed ''rude'' to discourage use of dc:creator. But is this right? Should we instead use a non DC property to relate people to documents?

A proposal.

* use dc:creator only as a relationship between a document and a simple flat name of (one of) its creators
* use other relationships (eg. propose foaf:maker) to relate a document to an Agent that made it
* write down some logical rules that express how foaf:maker and dc:creator relate
* don't use rdf:Seq, rdf:Alt, rdf:Bag with either property
* if we want to explicitly model ordering of authorship (eg. academic papers) we should invent markup to do so

The relation of foaf:maker to [http://webns.net/mvcb/generatorAgent admin:generatorAgent] (also known as [http://web.resource.org/rss/1.0/modules/admin/ RSS mod_admin]) was [http://ilrt.org/discovery/chatlogs/foaf/2003-07-24#T16-04-04 discussed in #foaf]. It was determined that admin:generatorAgent was a logical subproperty of foaf:maker, "a version of a software package that is a maker of a resource representation".

If we do this, we should be able to infer that 'N' is the dc:creator of 'D' wherever we see markup to the effect that
'D' has a foaf:maker of 'M' and that 'M' has a foaf:name of 'N'.

<pre>
?D dc:creator ?N .
implied by
?D foaf:maker ?M .
?M foaf:name ?N
</pre>
(''hmm, how to write this in proper machine-processable N3?'')

So, costs/benefits of this approach:

* (+) we have a single simple use for dc:creator
* (-) we appear less standards compliant, using the obscure foaf:maker property instead of the widely known dc:creator
* (+) we have a clear mapping of the one usage to the other
* (-) most RDF/XML tools cannot automatically understand such mappings
* (+) the meaning of the data is much clearer than for the various ways in which dc:creator has been (ab)used in RDF

What else can we do to help? Well the FOAF spec says that the foaf:name property is a sub-property of the more general, and widely known rdfs:label property. So whenever some text T is the foaf:name of a thing, RDF-smart tools can conclude that T is also the rdfs:label of that thing. This is a step towards the free-flowing interoperability that DC has been looking for. But ultimately we can't get away from the problems caused by the have-your-cake-and-eat-it approach to the use of dc:creator.

We need to decide whether dc:creator is so loose it can be used in all these different ways, or whether some are in error, or at the very least ''not best practice''.

<pre>
The proposal for FOAF usage is that only dc:creator as a simple textual value is best practice,
given what we know about the tools and technology at this time.
When we want to relate a document to a thing that made it, use foaf:maker (a proposed new
property, inverse of the existing foaf:made property).
</pre>

If this is accepted amongst FOAF, RDF, DC developers, some possible work items are suggested:

* within FOAF documents, replace our ambitious over-use of dc:creator with foaf:maker
* within Dublin Core, seek a new DC term which relates documents to agents (this is too useful to risk obscurity by solving in FOAF only)
* within RDF tools, work to allow automatic conversion between these different ways of describing the world

'''Note that there is a new [http://dublincore.org/documents/dc-rdf/ Dublin Core in RDF Draft] available that addresses this very issue.''' -- Mikael Nilsson
[[Category:Vocabulary_UsageGuidelines]]

UsingContactNearestAirport

2007-11-01T01:41:54Z

Admin: Automated import of articles

FOAF documents often contain a 'contact:nearestAirport' property. This page serves as a hub of references to further documentation on this property.

* [http://eric.perceive.net/blog/year/2002/month/12#a9 Pixel's writeup.]
* [http://d.hatena.ne.jp/kotastyle/20030707#p2 Instructions in Japanese.]
* [http://www.airnav.com/airports/ AirNav.com contains relevant information for air-related FOAF fields.]
* libby's docs?
* [http://www.wasab.dk/morten/2003/12/nearestAirport/ Finding a nearest airport]

From BkDeLong: So which is more appropriate in this case? The Megginson ns referenced by Pixel or the DAML namespace referenced below?
There seems to be wide agreement on using the DAML namespace, most notably because the Megginson URI is 404. --MortenFrederiksen

Here's an (abbreviated) fragment of http://jcwinnie.us/MT/weblog/foaf.rdf where we try to show how to use both foaf:based_near and the nearestAirport markup. They serve similar purposes, but are independent.

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
xmlns:contact="http://www.w3.org/2000/10/swap/pim/contact#"
xmlns:air="http://www.daml.org/2001/10/html/airport-ont#"
xmlns:wn="http://xmlns.com/wordnet/1.6/"
xmlns:daml="http://www.daml.org/2001/03/daml+oil#"
xmlns:pos="http://www.w3.org/2003/01/geo/wgs84_pos#"
xmlns:wot="http://xmlns.com/wot/0.1/"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:wordnet="http://xmlns.com/wordnet/1.6/"
xmlns:dc="http://purl.org/dc/elements/1.1/" >

<rdf:Description rdf:about="">
<dc:title>FOAF for Jonathan Smith</dc:title>
<dc:description>Friend-of-a-Friend description for Jonathan Smith</dc:description>
</rdf:Description>

<foaf:Person rdf:nodeID="jcwinnie">
<foaf:name xml:lang="en">Jonathan Smith</foaf:name>
<foaf:title>Wonderful Human Being</foaf:title>
<foaf:nick>jcwinnie</foaf:nick>
<foaf:made rdf:resource=""/>
<foaf:mbox rdf:resource="mailto:jonathan.w.smith@att.net"/>
<foaf:mbox_sha1sum>e155f403db629272e8f395a431a61bb60a31d69d</foaf:mbox_sha1sum>
<foaf:pubkeyAddress rdf:resource="http://jcwinnie.us/MT/weblog/public.asc" />
<foaf:homepage rdf:resource="http://jcwinnie.us/MT/weblog/"/>
<foaf:weblog rdf:resource="http://jcwinnie.us/MT/weblog/"/>
<foaf:img rdf:resource="http://jonathansmith.swiki.net/.uploads/me1996.jpg"/>
<foaf:phone rdf:resource="tel:607-770-0911"/>
<foaf:schoolHomepage rdf:resource="http://www.marywood.edu"/>
<foaf:birthDate>1949-12-21</foaf:birthDate>
<foaf:myersBriggs>INFP</foaf:myersBriggs>
<foaf:based_near>
<pos:Point>
<pos:lat>42.1236</pos:lat>
<pos:long>-75.9618</pos:long>
</pos:Point>
</foaf:based_near>
<contact:nearestAirport>
<wn:Airport>
<air:name>Greater Binghamton Edwin A Link Fld</air:name>
<air:iataCode>BGM</air:iataCode>
<air:icaoCode>KBGM</air:icaoCode>
<air:sameIndividualAs rdf:resource="http://www.daml.org/cgi-bin/airport?BGM"/>
<air:location>Binghamton, New York, United States</air:location>
<air:latitude>42.20861111111111</air:latitude>
<air:longitude>-75.97972222222222</air:longitude>
<air:elevation>1636</air:elevation>
</wn:Airport>
</contact:nearestAirport>
</foaf:Person>
</rdf:RDF>
</pre>
[[Category:Vocabulary_UsageGuidelines]]

Using based near

2007-11-01T01:41:43Z

Admin: Automated import of articles

From FoafExamples, showing how to use the foaf:based_near property.

The foaf:based_near relationship links a "spatial thing" (anything that can ''be somewhere'') to a point in space, typically specified using the geo:lat / geo:long [http://www.w3.org/2003/01/geo/wgs84_84# geo-positioning vocabulary] (see [http://esw.w3.org/topic/GeoInfo GeoInfo] in the W3C semweb wiki for details).

Here we show it relating a person to a point:

Taking sample data from http://www.jasoncook.com/foaf.rdf and replacing the geo markup there, since that namespace doesn't seem to exist:

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<foaf:Person rdf:ID="Jason">
<foaf:name>Jason Cook</foaf:name>
<foaf:title>Mr</foaf:title>
<foaf:based_near>
<geo:Point geo:lat="41.8833" geo:long="12.5"/>
</foaf:based_near>
</foaf:Person>
</rdf:RDF>
</pre>

Note that this same markup could be applied to other spatial things, such as shops, artifacts etc.

We do not say much about what 'near' means in this context; it is a 'rough and ready' concept. For a more precise treatment, see the [http://esw.w3.org/topic/GeoOnion GeoOnion vocab] design discussions.
----
CategoryTutorial
[[Category:Vocabulary_UsageGuidelines]]

WhyWordnetIsCool

2007-11-01T01:41:30Z

Admin: Automated import of articles

The Wordnet lexical database can be used in RDF for describing the kinds of things depicted in photos.

Here is an example fragment of RDF to show it's usage. Note the word-sense number used with Film-5; Wordnet has various senses associated with that word.

<pre>
<?xml version="1.0"?>
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:wn="http://xmlns.com/wordnet/1.6/"
xmlns:foaf="http://xmlns.com/foaf/0.1/">
<foaf:Image rdf:about="http://rdfweb.org/people/danbri/media/2003/08/1/376j0234.jpg">
<foaf:depicts><wn:Cowboy_hat/></foaf:depicts>
<foaf:depicts><wn:Film-5/></foaf:depicts>
</foaf:Image>
</rdf:RDF>
</pre>
For example, listed below a bunch of photos, followed by some quick searches in Wordnet (v 1.6) for relevant classes (nouns). This gives a rough idea of the terminological coverage of Wordnet.

http://rdfweb.org/people/danbri/media/2003/08/1/

The [http://xmlns.com/2001/08/wordnet/ xmlns Wordnet RDF namespace] is used in the FoafProject to provide thousands of RDF classes named after common nouns from the English language. See [http://www.wikipedia.org/wiki/WordNet wikipedia's Wordnet entry] for more on Wordnet.
(Todo: actually catalogue the images in RDF... also link to mattb's stuff at [http://hackdiary.com/ hackdiary] and [http://picdiary.com/ picdiary].

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376l0270.jpg
<pre>
danbri@fireball:~$ wn 'balloon' -n2 -hypen

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun balloon

Sense 2
balloon
=> lighter-than-air craft
=> aircraft
=> craft
=> vehicle
=> conveyance, transport
=> instrumentality, instrumentation
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing

</pre>

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376i0227.jpg
<pre>
danbri@fireball:~$ wn 'digital watch' -hypen

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun digital_watch

1 sense of digital watch

Sense 1
digital watch
=> watch, ticker
=> timepiece, timekeeper
=> measuring instrument, measuring system, measuring device
=> instrument
=> device
=> instrumentality, instrumentation
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing

</pre>

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376j0234.jpg
<pre>
Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun cowboy_hat

1 sense of cowboy hat

Sense 1
cowboy hat, ten-gallon hat
=> hat, chapeau, lid
=> headdress, headgear
=> clothing, clothes, apparel, vesture, wearing apparel, wear, article of clothing
=> covering
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing
=> consumer goods
=> commodity, trade goods, goods
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing

</pre>

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376i0228.jpg
<pre>
danbri@fireball:~$ wn 'beer can' -hypen

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun beer_can

1 sense of beer can

Sense 1
beer can
=> can, tin, tin can
=> container
=> instrumentality, instrumentation
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing

</pre>

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376m0248.jpg
<pre>
danbri@fireball:~$ wn 'suspension bridge' -hypen

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun suspension_bridge

1 sense of suspension bridge

Sense 1
suspension bridge
=> bridge, span
=> structure, construction
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing

</pre>

http://rdfweb.org/people/danbri/media/2003/08/1/images/thumbs/376j0260.jpg
<pre>
danbri@fireball:~$ wn 'bumper_car' -hypen

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun bumper_car

1 sense of bumper car

Sense 1
bumper car, Dodgem
=> vehicle
=> conveyance, transport
=> instrumentality, instrumentation
=> artifact, artefact
=> object, physical object
=> entity, physical thing
=> whole, whole thing, unit
=> object, physical object
=> entity, physical thing
</pre>

[[Category:Vocabulary_OtherVocabs]]

SpeaksReadsWrites

2007-11-01T01:41:17Z

Admin: Automated import of articles

= Speaks, Reads, and Writes =

The basic idea is:

namespace declaration:: xmlns:lang="http://purl.org/net/inkel/rdf/schemas/lang/1.1#"
lang:speaks:: Indicates that the Person can '''speak''' in this language
lang:reads:: Indicates that the Person can '''read''' this language
lang:writes:: Indicates that the Person can '''write''' in this language
lang:masters:: Indicates that the Person can '''speak, read and write''' in this language

The language is given with [http://lcweb.loc.gov/standards/iso639-2/langcodes.html ISO-639-1 codes.]

|| de || German || fr || French ||
|| en || English || it || Italian ||
|| es || Spanish || ja || Japanese ||

Example:

<pre>
<lang:reads>de</lang:reads>
<lang:writes>de</lang:writes>
<lang:masters>en</lang:masters>
</pre>

Remember: You need to include the namespace declaration as well! (<pre>xmlns:lang="http://purl.org/net/inkel/rdf/schemas/lang/1.1#"</pre>)

See the [http://f14web.com.ar/inkel/rdf/schemas/lang/index.en.html Speaks, Reads, and Writes page] and the [http://purl.org/net/inkel/rdf/schemas/lang/1.1 schema document] for more details.

Extension by Leandro Mariano L�pez.

----
FoafExtension

== Discussion ==

(none yet!)

[[Category:Vocabulary_OtherVocabs]]

SpaceNamespace

2007-11-01T01:41:04Z

Admin: Automated import of articles

= Locations and Spaces =

This document describes some RDF vocabulary that can be used for modelling locations and spaces. The basic idea is to take a skeletal notion of locations, exits, entries etc from MOO modelling, and augment this with more precise representations of location (latlong etc) and with additional annotations (such as pointers to web content, audio annotations etc).

Nearby vocab
* @@that rss thing
* Zool's [http://space.frot.org/ spacenamespace] page, with maps of england and london and irc/aim interface.
* AccessiblePlanet wiki page
* http://www.headmap.org/
* [http://www.guardian.co.uk/online/webwatch/story/0,12455,858719,00.html a grauniad piece]
* [http://undergroundlondon.com/antimega/archives/000012.html]FOAP

= MOO-based vocab =

Some classes and properties for representing MOO content. this is a pretty literal representation of some core machinery from the Xerox MOO core. It stops more or less at the point where MOO begins to mix code into the location descriptions.

The basic structure is organised around 'locations' and 'exits'. Each location has several exits. Each exit is an exit *from* one location *to* another. The
'from' and 'to' properties of an exit capture this.

see: old rough example, http://fireball.danbri.org/people/danbri/s-rdfweb/2002/foaf/places/moo/sample_places.rdf

== Classes ==

moo:Location, moo:Exit

In addition, we use Wordnet types for all nouns. (wn:Tree, wn:Box etc...).

== Properties ==

The following properties are used. These should be re-organised into an actual schema.

moo:oid, moo:name, moo:description, moo:content, moo:locexit, moo:from, moo:to, moo:player_msg, moo:loc_msg, moo:direction, moo:location, moo:contains, moo:ownerid.

== Other Stuff ==

A dump of other browser windows I have open:

http://www.inform-fiction.org/examples/Advent/Advent_2_com.html
http://www.inform-fiction.org/examples/Advent/Advent_2_inv.html

== Cambridge Police MA, USA ==

See http://www.cambridgepolice.org/ under Neighbourhood Profiles

[[Category:Vocabulary_OtherVocabs]]

DOAC

2007-11-01T01:40:52Z

Admin: Automated import of articles

Description of a Career

to do

[http://ramonantonio.net/doac/ DOAC Vocabulary Specification]
[[Category:Vocabulary_OtherVocabs]]

XsltDocumenationIssue

2007-11-01T01:40:38Z

Admin: Automated import of articles

XsltDocumentationIssue

Current status: open
Owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

[http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2004Jan/0003.html mail from Dan Connolly on RDF and XSLT]

[http://gmpg.org/xfn/xfn-foaf XFN and foaf, Eric A. Meyer]
[http://rdfweb.org/pipermail/rdfweb-dev/2003-December/012236.html XFN and foaf, rdfweb-dev]
[http://www.ldodds.com/blog/archives/000105.html XFN and foaf, Leigh Dodds]

----

Broadly, each issue description should:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

WordnetIssue

2007-11-01T01:40:26Z

Admin: Automated import of articles

WordnetIssue
FoafVocab

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

The RDF used to describe Wordnet nouns as RDF classes is broken.
It (due to Perl bug) confuses terms with the synonym-sets that group them.

Known problem, work is in progress on Ruby and Perl rewrites.

To resolve this, we need to create an anonymous or numerically named class that
stands for the grouping of all the classes associated with a synonym set. Or
perhaps to associate a class named after the first term from a synset with the
super-class? Also we should make sure that the server returns wellformed XML from URLs that
result in empty wordnet results.

Still todo:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

[[Category:Vocabulary_Issues]]

Vocabulary

2007-11-01T01:40:16Z

Admin: Automated import of articles

Pointers to information and discussion on FOAF syntax, and vocabulary, and its extensions

* The [http://xmlns.com/foaf/0.1/ FOAF specification] is the main reference point for the FOAF vocabulary. See [http://www.ldodds.com/blog/archives/000047.html foaf2doc] for an alternative view of this documentation.
* FoafVocab (rough notes on the FOAF vocabulary)
* FoafExtensions includes links to extensions to the FOAF vocabulary.
* FoafExamples has some worked examples that illustrate how to apply the FOAF vocabulary.
* Those of you new to writing RDF in XML may want to take a look at [http://rdfweb.org/topic/FOAFSyntaxTips FOAFSyntaxTips]
* RdfSyntaxFoafIntro -- introduction to RDF syntax for FOAF users

Some suggested additions include:

* [http://rdfweb.org/topic/FOAFAlarmClock FOAFAlarmClock] -- wake up slacker!
* [http://rdfweb.org/topic/DOAC Description of a Career] (DOAC) -- share your curriculum information into your FOAF file.

Related vocabularies:

* NatFoafExample
[[Category:Vocabulary_Issues]]

UnAnsweredFAQ

2007-11-01T01:40:03Z

Admin: Automated import of articles

Got this in my blog comments :

''FOAF is interesting to me, but how is one supposed to add *friends*? What qualifies one as a *friend*? And I gather that it is possible for you to be my friend but me not be yours. FOAF is designed to be selfless I guess....''

I gave a vague rambling reply and pointed to FOAF-a-matic.

And another :

''I got turned on to FOAF-o-matic six degrees (or one or two) from your blog. I was hesitant to say I knew anyone for precisely the reason you outlined above. I joined the blogosphere only back in march of this year, but I've been fairly active within the some of the same circles you frequent. So while I may *feel* like I know Danny Ayers, Sam Ruby, Mark Pilgrim, Dare Obasanjo, Timothy Appnel, Dave Winer, and Tim Bray -- I really don't. At least I have never met any of you in person (sadly South Florida sees precious few technology conferences). What, then, is the value of FOAF for me?''

-- DannyAyers

----

What is the copyright policy of this wiki? Is it open content? public domain, GFDL, or Creative Commons-licensed? Thanks,

-- BayleShanks
[[Category:Vocabulary_Issues]]

TrustVocabIssue

2007-11-01T01:39:48Z

Admin: Automated import of articles

TrustVocabIssue

Current status: open
Owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

''This was originally a duplicate of PgpVocabUndocumentedIssue -- changed to concern other issues specific to wot.'' --MortenFrederiksen

See also [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012787.html discussion thread on rdfweb-dev] and the [http://lists.w3.org/Archives/Public/semantic-web/2005Feb/0128.html Semantic Web Publishing (SWP) vocabulary].

== General Issues ==

The [http://xmlns.com/wot/0.1/ wot schema] could do with some OWLification.

Several literal properties should be declared as datatype properties (as already indicated with a comment).

Perhaps some integration with iCal/RDF for signature events would be in order, also to be able to verify by e.g. codepiction that a signature event is reasonable.

Instances of ''PGP'' should be substituted with ''PGP/GPG'' or something similar, to avoid exclusion.

It seems tempting to relate the name, comment and email fields of a key to the user of the key instead of to the key itself, as it most often will be the same. That is, the name field of a key usually contains the name of its user. However, for agents with multiple keys this presents a problem, e.g. for FoafBot:
<pre>
<PubKey>
<hex_id>6C746DD1</hex_id>
<identity>
<foaf:Agent>
<foaf:name>FOAFBot (#bots instance)</foaf:name>
<foaf:mbox rdf:resource="mailto:foafbot@usefulinc.com"/>
</foaf:Agent>
</identity>
</PubKey>
<PubKey>
<hex_id>6C7F734E</hex_id>
<identity>
<foaf:Agent>
<foaf:name>FOAFBot (Key used by the OPN #foaf instance of FOAFbot)</foaf:name>
<foaf:mbox rdf:resource="mailto:foafbot@usefulinc.com"/>
</foaf:Agent>
</identity>
</PubKey>
</pre>
The above seems fine at first, but then we realize that the identifying properties of ''foaf:mbox'' causes the two agents to be merged, leaving a single agent with two names, and no way to differentiate between the two keys. It could be argued that foafbot shouldn't use the same email address for multiple instances, but this is how it is.
The above should instead be expressed as follows:
<pre>
<PubKey>
<hex_id>6C746DD1</hex_id>
<dc:title>FOAFBot (#bots instance)</dc:title>
<identity>
<foaf:Agent>
<foaf:name>FOAFBot</foaf:name>
<foaf:mbox rdf:resource="mailto:foafbot@usefulinc.com"/>
</foaf:Agent>
</identity>
</PubKey>
<PubKey>
<hex_id>6C7F734E</hex_id>
<dc:title>FOAFBot (Key used by the OPN #foaf instance of FOAFbot)</dc:title>
<identity>
<foaf:Agent>
<foaf:name>FOAFBot</foaf:name>
<foaf:mbox rdf:resource="mailto:foafbot@usefulinc.com"/>
</foaf:Agent>
</identity>
</PubKey>
</pre>
When generating RDF automagically from keyrings, the name of the agent or the name of the key is not readily available, there is just one string. In that case, the name property should be assigned to the key, leaving it off the user, since the identifying ''foaf:mbox'' property on the user opens opportunities for others to state the (correct) name of the user.

== Classes ==

The '''Endorsement''' class is currently commented out of the schema. Its purpose/meaning doesn't seem completely clear, but seems to serve as the type for objects of an ''assurance'' predicate, that is, documents that contain a detached ascii signature.

The '''User''' class should be a subclass of foaf:Agent instead of foaf:Person, to allow for bots like FoafBot to have their own key(s). This also fits somewhat nicer with the comment for the '''PubKey''' class, which currently states that it represents ''a person's or organization's PGP public key''.

A new class '''EncryptedDocument''' would be handy, to serve as the type of objects of an ''encryptedTo'' predicate (see usage in [http://usefulinc.com/foaf/encryptingFoafFiles PGP Encrypting FOAF Files]). This would also help systems avoid republishing statements obtained from encrypted documents.

Instances of the '''PubKey''' class could be assigned a URI, in which case it should identify a document with the ascii version of the public key. Alternatively, the ''pubKeyAddress'' property could be relaxed and used for this.

== Properties ==

The ''hex_id'' property may be considered to be an '''owl:InverseFunctionalProperty''', but in reality there are only 16^8^ = 4.294.967.296 different IDs. As such, this property should not be declared as an IFP.

In contrast, the chances for a collision between two keys on the property ''fingerprint'' should be negligable, so this should be declared to be an IFP.

The property ''identity'' relates a key to its user, so this is essentially the inverse of PgpVocabUndocumentedIssue, and should be declared as such when that property is coined/implemented. ''identity'' should be declared as a '''owl::FunctionalProperty''', since a key can only belong to one user (even if it's an organization or group).

The domain of the ''signed'' property should be PubKey, not User, as a user may have more than one key. This is also what is suggested by the wording in the associated comment.

The ''signerLongHexID'' property should be replaced simply with a ''signer'' property. Aside from name casing issues, it seems much better to have a property that relates the signature event to a key rather than to a literal. The referenced key should of course have a ''hex_id'' property itself. The ''signer'' property should thus have a range of ''PubKey'' instead of literal. Note that this does not make ''signer'' an inverse of ''signed'', as ''signer'' relates a signature to the key that is used to sign the signee, the ''signed'' key.

The ''assurance'' property should have a range of '''foaf:Document''', and either a similar range, or a range of the currently out-commented class '''Endorsement'''.

The property ''pubkeyAddress'' is currently being misused according to its definition, as it's being used both as a property off a '''foaf:Person''' and a '''PubKey''', where it should be used as a property off a '''foaf:Document'''. It seems that the best way out is to assign it a domain of '''PubKey''' and to create a new property ''endorser'', so that a document is related by ''assurance'' to an endorsement, which in turn is related to the signing key by ''endorser''. The range of ''pubKeyAddress'' would then be '''foaf:Document''', thus having it relate a public key to a document containing an ascii version of the public key, suitable for import into a key ring. This approach (''endorser'') also makes it possible for a document to have multiple signatures.

Continuing along the same lines, a property ''encrypter'' should be added to the schema, to relate an encrypted document to the key that has encrypted it. Domain should be '''EncryptedDocument''', range should be '''PubKey'''.

The property ''encryptedTo'', as exemplified in [http://usefulinc.com/foaf/encryptingFoafFiles PGP Encrypting FOAF Files], should be included formally in the schema, with a domain of '''foaf:Document''' and a range of '''PubKey'''.

== A Revised Schema ==

* [http://xmlns.com/wot/0.1/ Original wot schema]
* [http://www.wasab.dk/morten/2004/02/wot.rdf Revised wot schema]
* [http://xml.mfd-consult.dk/ws/2003/01/rdfs/?rdfs=http://www.wasab.dk/morten/2004/02/wot.rdf Prettier version]

== Complete Example ==

An example document utilizing all the classes and properties of the revised wot vocabulary.

<pre>
<rdf:RDF xmlns="http://xmlns.com/wot/0.1/"
xmlns:foaf="http://xmlns.com/foaf/0.1/"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
<foaf:Document rdf:about="http://example.com/doc.html">
<dc:title>Example Document</dc:title>
<assurance>
<Endorsement rdf:about="http://example.com/doc.html.asc">
<dc:title>Detached signature for "Example Document"</dc:title>
<endorser rdf:nodeID="KeyA"/>
</Endorsement>
</assurance>
</foaf:Document>
<PubKey rdf:nodeID="KeyA">
<hex_id>3756EA0B</hex_id>
<length>1024</length>
<fingerprint>04FF F3AC 57DF 217C 6D38 3DBC 0110 FB92 3756 EA0B</fingerprint>
<pubkeyAddress rdf:resource="http://foaf.dk/key.asc"/>
<identity>
<User>
<foaf:name>Web Service (foaf.dk)</foaf:name>
<foaf:mbox_sha1sum>a714a83db77c6ce85211beb56599adf2c4eaa62f</foaf:mbox_sha1sum>
</User>
</identity>
<signed>
<SigEvent>
<signer rdf:nodeID="KeyB"/>
<sigdate>2004-02-18</sigdate>
</SigEvent>
</signed>
</PubKey>
<PubKey rdf:nodeID="KeyB">
<hex_id>E3C9EC9D</hex_id>
<length>1024</length>
<fingerprint>2A 99 C4 9F 34 82 AE CF 11 09 FA 52 A6 FF 2F C2</fingerprint>
<identity>
<User>
<foaf:name>Morten Frederiksen</foaf:name>
<foaf:mbox_sha1sum>65b983bb397fb71849da910996741752ace8369b</foaf:mbox_sha1sum>
</User>
</identity>
</PubKey>
<EncryptedDocument rdf:about="http://example.com/doc.asc">
<dc:title>Example Encrypted Document</dc:title>
<encryptedTo rdf:nodeID="KeyB"/>
<encrypter rdf:nodeID="KeyA"/>
</EncryptedDocument>
</rdf:RDF>
</pre>

----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

SubscribesToIssue

2007-11-01T01:39:38Z

Admin: Automated import of articles

SubscribesToIssue

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

A property for listing the person's mailing list, usenet and RSS news
subscriptions. A use case is using it to minimise the number of crossposts when
mailing.

* [http://dannyayers.com/archives/000795.html Danny Ayer's weblog entry]
* Assigned To: danbri at rdfweb.org
* [http://rdfweb.org/pipermail/rdfweb-issue-archive/2003-February/000006.html rdfweb-issue-archive]

''Something in this vein is useful. Quite how we do it probably needs more
discussion. Many folk want to represent groups, such as the membership of a
mailing list or other online community. In some cases we want to do that
indirectly, eg. by indicating the sha1sum of the mailboxes of the listmembers,
to avoid giving away too much information. So there may be a general notion of a
'Group' that gets defined alongside such machinery for picking out the group
members.

One thing to explicitly avoid is any assumption that all group members 'read'
each item sent to the list/newsgroup/etc. People will be wary of this, example
might be if a patent claim is sent to a mailing list, we shouldn't assume each
listmember reads each mailing list posting.

Perhaps we could afford some specific markup for email and news groups, and have
foaf:subscriber_mbox or foaf:subscriber_mbox_sha1sum be properties of such groups?''
(http://rdfweb.org/pipermail/rdfweb-issue-archive/2003-February/000008.html Danbri, 2003-02-07 00:40])

''I'd much rather see a way for a group itself to express it's membership first
and use that. Better to have a way for the concept of a 'group' to be defined
and to express it's members. Then have a user's foaf state it's membership in
said group as a bidirectional linking factor. This way the group's definition
of being a mailing list might then infer than contacting members found across
multiple groups might be wasteful. Especially if the groups can expose their
own contacting mechanisms.''
([http://rdfweb.org/pipermail/rdfweb-issue-archive/2003-February/000026.html wkearney99 at hotmail.com 2003-02-28 21:05])

[[Category:Vocabulary_Issues]]

SubscribesToForListsIssue

2007-11-01T01:39:24Z

Admin: Automated import of articles

SubscribesToForListsIssue

current status: open

owner:danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

[http://rdfweb.org/pipermail/rdfweb-issue-archive/2003-August/000066.html Would be good if someone could have a crack at expressing mailing list membership etc using the groups mechanism...]

----

Each BlahBlahIssue page can be created from the IssueTemplate; you can delete the general guidelines and replace them with content as seems appropriate.

Broadly, each issue description should:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

SolicitRoadMapProposals

2007-11-01T01:39:12Z

Admin: Automated import of articles

'''How should we proceed?'''

'''Most recent 'root comment' first (conversation threads in descending order):'''

---

How about starting by enumerating the properties of the most popular existing sites, then seeing what kind of class hierarchy "falls out"? This gets us moving (embrace and extend!), and maximizes usability, as people, when migrating their profiles, can just choose the "view" with which they are most comfortable (FOAFster, FOAFLinkedIn, FOAFTribe, etc. -- all of which could be sub-classes of "Core FOAFster"). -- Frank Ruscica

---

For the moment I'll copy over my e-mail to [http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012379.html rdfweb-dev]; when I get some time, I can break things down a bit. -- Nick Knouf

Just for starters, let's think about the properties that you can enter on a site like Friendster (and it'll be no secret that I'm talking about my own profile, but that's not pertinent to the thread :-) ).

Friendster offers free-text input of favorite music, movies, books, and TV shows. Separate items are delineated with commas and form clickable search terms to find others with the same interest. This seems to be a perfect place to include some of the ideas of the Charette Relationship Set (CRS) [1], which can describe things that one has or wants, hobbies, and stuff that you're interested in. There should be some tie-in with other media-specific schemas (and I'm not saying this is what should be used, but stuff like the MusicBrainz Metadata Initiative [2] for music could be used).

Okay, there's a whole range of work to be done with the media-specific schemas, but let's move on to more superficial things :-)

Physical attributes like hair color, complexion, and the like probably best come from governmental work like Stephen is looking at. I'm not sure of previous efforts to formalize definitions of someone's height, weight, etc.; with those properties, however, we need a good way to describe the units. Someone looking for information on me would want to know if my weight of "150" was in pounds or kilos ;-) I asked about this on www-rdf-interest in December [3] and was referred to some work done at JPL [4] to describe the units in a very elegant way. Making this work in practice and making the ontology validate as DL is somewhat more difficult, but I'm sure it can be worked out.

Geographic information can probably come from existing ontologies (which others on this list have much more experience than me).

What doesn't seem to be out there is good semantic definitions of "Interested in meeting people for" (e.g., dating, serious relationship, activity partners, etc.), "Who I want to meet", and so on. That's probably the crux of the problem. This is going to run into all sorts of cultural, religious, and geographic concerns as well; not that it means we shouldn't try it, but it's something to keep in mind.

I do believe that this is a case where pulling terms from a large number of ontologies and namespaces is going to be useful and perhaps necessary. Describing a dating service is basically an attempt to fully describe a human being, much beyond what FOAF does (and I think because of that most of these additions or samplings should not be rolled into the FOAF namespace). I'm afraid that using a single namespace is going to make this blossom into something like SUMO [5]; I think SUMO is very interesting, it's just not what we're looking for (in my view).

We ought to be realistic here: after thousands of years of the written word, no-one has come up with the _ideal_ way of describing someone. Everything we do will only be an approximation. Of course, we should try and make it a damn good one :-)

Cheers,

Nick

[1] [http://www.charette.com/SemanticWeb/crs.html]
[2] [http://www.musicbrainz.org/MM/]
[3] [http://lists.w3.org/Archives/Public/www-rdf-interest/2003Dec/0046.html]
[4] [http://sweet.jpl.nasa.gov/sweet/units.owl]
[5] [http://ontology.teknowledge.com/]
[[Category:Vocabulary_Issues]]

SchemaTranslationIssue

2007-11-01T01:38:59Z

Admin: Automated import of articles

SchemaTranslationsIssue

Current status: open
Ownder: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

Some links:

[http://www.ldodds.com/blog/archives/000061.html foaf-a-matic translations]
[http://rdfweb.org/pipermail/rdfweb-dev/2002-September/002236.html Edd's FOAF article in Japanese]

----

Broadly, each issue description should:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

QuoteIssue

2007-11-01T01:38:49Z

Admin: Automated import of articles

QuoteIssue

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

The recent Pew Internet survey on instant messaging noted that the most popular form of content added to IM profile pages (think the ICQ website) is "funny quotes or other sayings" that the person identifies with in some way. The numbers: 42% of profile creators included quotes, whereas only 18% included links to websites of interest (think foaf:interest). So it seems that it would be good for FOAF to include a foaf:quote property of some kind.

Originally described here: http://www.saint-andre.com/blog/2004-09.html#2004-09-17T09:25

See also: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013692.html

Issue owner: Peter Saint-Andre

TODO:

* proposed markup
* test cases
* examples

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

PreferredContactIssue

2007-11-01T01:38:33Z

Admin: Automated import of articles

PreferredContactIssue

Current status: open
Owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

2004-01-12 proposal by Julian Bond: foaf:preferredContact, to provide a public contact point where a person is happy to receive unsolicited messages from people who have found their FOAF. (email/phone/IM/etc) ([http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012453.html rdfweb-dev mail])

----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

PointingFromPersonToGroup

2007-11-01T01:38:21Z

Admin: Automated import of articles

There is some debate in how to point from a Person to a Group (FoafGroups).

There seem to be two broad modes of thought:
* Link the person to the group with a new property in a FoafExtension.
* Create a group within the FOAF file, with a see-also to the FOAF file containing the full description.

There's presently an issue ticket assigned to this: MemberVocabIssue.

The first is obvious; a brief note on the second-

The second works something like this:

<pre>
<rdf:RDF ...>

<foaf:Person rdf:nodeId="me">
<foaf:name>YOUR NAME HERE</foaf:name>
...
...
(YOUR FOAF INFORMATION)
...
...
</foaf:Person>

<foaf:Group>
<foaf:name>NAME OF GROUP YOU BELONG TO</foaf:name>
<rdfs:seeAlso rdf:resource="URL OF FOAF FILE FOR GROUP"/>

<foaf:member>
(SOME WAY OF SAYING, "ME, IDENTIFIED IN THE NODEID ABOVE")
</foaf:member>

</foaf:Group>

</rdf:RDF>
</pre>
[[Category:Vocabulary_Issues]]

PgpVocabUndocumentedIssue

2007-11-01T01:38:11Z

Admin: Automated import of articles

PgpVocabUndocumentedIssue

current status: open
owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

see
http://ilrt.org/discovery/chatlogs/foaf/2003-07-27#T01-26-03
and
TrustVocabIssue (re the fact that ''wot:identity'' is the inverse of the "missing" property).

<pre>
<Cardinal> Hmm. Has a property for public pgp key ever been suggested?
<danbri> yes, i've been using it from the start... darn, another one that never
made it into the schema...
* Cardinal ahs.
<danbri> http://rdfweb.org/people/danbri/rdfweb/danbri-foaf.rdf <pubkeyAddress
rdf:resource="http://rdfweb.org/people/danbri/danbri-pubkey.txt"/>
<danbri> nothing for inlining the pubkey though
<danbri> i guess a url ok
<danbri> logger_2, bookmark?
<logger_2> See http://ilrt.org/discovery/chatlogs/foaf/2003-07-27#T01-26-03
</pre>

[[Category:Vocabulary_Issues]]

PersonWeblogRssDocumentationIssue

2007-11-01T01:37:58Z

Admin: Automated import of articles

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.
* Status: Active ([http://rdfweb.org/pipermail/rdfweb-dev/2005-March/013959.html discussion on rdfweb-dev])
* Contact: mortenf

== Summary ==

How to "connect" a person or weblog with an RSS feed?

When doing (social) network analysis like [http://www.livejournal.com/users/keybuk/7112.html Scott James Remnant], it's often useful to be able to connect people or their weblogs with RSS feeds. A [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012543.html discussion about this on rdfweb-dev] lead to a [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012548.html longish post by danbri] on the subject. In addition to the knowledge that could be inferred directly , RSS feeds and FOAF documents often contain links to other document through the use of ''rdfs:seeAlso'', making it easier to discover new knowledge indirectly as well.

Related to this issue is the SubscribesToIssue (and the SubscribesToForListsIssue), which seems to also cover the [http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012491.html issue regarding blogrolls], and the KnowsAgentVocabIssue, regarding Typepad and the range of ''[http://xmlns.com/foaf/0.1/index.html#term_knows foaf:knows]''.

== Problems ==

There are many ways to describe the connections between people or weblogs and RSS feeds, some of which are described in the [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012548.html longish post by danbri].

The problem with this issue doesn't seem to be to choose one canonical way, but rather to demonstrate when one might want to use one approach rather than another.

== History ==

''This section is mostly copy/paste from the [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012548.html longish post by danbri].''

''[http://xmlns.com/foaf/0.1/index.html#term_made foaf:made]'' and ''[http://xmlns.com/foaf/0.1/index.html#term_maker foaf:maker]'' have been around for a while, and at some point Edd Dumbill [http://usefulinc.com/foaf/iMadeThis showed how to use them in HTML], as well as demonstrating a way of saying "I created my weblogs' RSS feed":

<pre>
<rss:channel rdf:about="http://usefulinc.com/edd/blog/rss">
<foaf:maker>
<foaf:Person>
<foaf:mbox rdf:resource="mailto:edd@usefulinc.com" />
</foaf:Person>
</foaf:maker>
</rss:channel>
</pre>

This is a document (channel) centric approach -- the person centric approach would be to use ''foaf:made'' instead:

<pre>
<foaf:Person>
<foaf:mbox rdf:resource="mailto:edd@usefulinc.com" />
<foaf:made>
<rss:channel rdf:about="http://usefulinc.com/edd/blog/rss"/>
</foaf:made>
</foaf:Person>
</pre>

Later on, the [http://www.hackdiary.com/projects/chumpologica/ chumpologica] started using an RDF blogroll to manage feeds:

<pre>
<foaf:Agent rdf:nodeID="id2246022">
<foaf:name>Danny Ayers</foaf:name>
<foaf:weblog>
<foaf:Document rdf:about="http://dannyayers.com/">
<dc:title>Raw Blog by Danny Ayers</dc:title>
<rdfs:seeAlso>
<rss:channel rdf:about="http://dannyayers.com/feed/rdf">
<foaf:maker rdf:nodeID="id2246022"/>
<foaf:topic rdf:resource="http://www.w3.org/2001/sw/"/>
<foaf:topic rdf:resource="http://www.w3.org/RDF/"/>
</rss:channel>
</rdfs:seeAlso>
</foaf:Document>
</foaf:weblog>
<foaf:interest rdf:resource="http://www.w3.org/2001/sw/"/>
<foaf:interest rdf:resource="http://www.w3.org/RDF/"/>
</foaf:Agent>
</pre>

At the core, this is the same approach, with the addition of the weblog being associated with the person through the use of ''[http://xmlns.com/foaf/0.1/index.html#term_weblog foaf:weblog]'' (and with interests/topics, see [http://rdfweb.org/mt/foaflog/archives/000052.html Pages about people] and the TopicInterestIssue, but also note danbri's point regarding the range of ''[http://xmlns.com/foaf/0.1/index.html#term_interest foaf:interest]'').

Even later, the [http://www.wasab.dk/morten/blog/archives/2004/07/05/wordpress-plugin-foaf-output WordPress FOAF Output Plugin] has adopted the samme model.

== Options ==

FAQ:: One way of resolving this issue would be merge this page with more examples and danbri's points about groups, agents, documents and feeds, creating a document that would be ideal for an FAQ or a weblog post. This would require no changes to existing documents or applications, and would rely on ''rdfs:seeAlso'' being the preferred way of linking. This would however require a rewrite/merger, estimated at about 1 hours work.

Drop:: The issue could be resolved by dropping it, considering the problem of documentation covered by the now widely used ''foaf:maker'' and/or ''foaf:made''. The estimated work load of this option is about 0.

foaf:weblogFeed:: Another, more direct, approach, would be to invent a new predicate, relating an RSS feed to the weblog it summarizes, as has been [http://rdfweb.org/pipermail/rdfweb-dev/2004-February/012547.html proposed by Dom Ramsey]. This doesn't solve the problem with documentation and has an impact on the usefulness of ''rdfs:seeAlso'', and would require changes to at least some applications out there. The work load for this option hasn't been estimated.
[[Category:Vocabulary_Issues]]

OwlImportsIssue

2007-11-01T01:37:45Z

Admin: Automated import of articles

''current status: open''. This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

'''The problem''': The FOAF RDFS file imports the RDFS and OWL ontologies.

Quoting from http://xmlns.com/foaf/0.1/index.rdf :

<owl:imports rdf:resource="http://www.w3.org/2000/01/rdf-schema"/>

<owl:imports rdf:resource="http://www.w3.org/2002/07/owl"/>

This is not necessary and not recommended. Quoting from http://www.w3.org/TR/owl-guide/ :

"Note that in order to use the OWL vocabulary you do not need to import the owl.rdf ontology. In fact, such an import is not recommended."

'''The solution''': I suggest removing the two imports from the RDFS file.

'''Discussion on rdfweb-dev''':

* RichardCyganiak raises issue: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013672.html
* DanBrickley agrees: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013673.html
* RonAlford agrees: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013674.html

(In case you wonder why anyone should care: A practical reason against importing the ontologies, and the reason why I noticed in the first place, is this: When you develop a generic RDFS/OWL vocabulary viewer or editor, you want to give the user the option to also view/edit classes and properties from imported ontologies. But the option to view/edit the OWL and RDFS classes and properties is absolutely useless and might confuse the user. Therefore, ontologies that do not import the RDFS and OWL files are better.)

-- RichardCyganiak
[[Category:Vocabulary_Issues]]

OnlineAccountHomepageIssue

2007-11-01T01:37:33Z

Admin: Automated import of articles

OnlineAccountHomepageIssue

current status: open

current owner: leigh@ldodds.com

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

Summary: See [http://rdfweb.org/pipermail/rdfweb-dev/2005-January/013935.html Leigh's original mail to rdfweb-dev].

=== foaf:accountHomepage ===

Currently in FOAF we can tie a foaf:Person to a description of some account they hold on a service:

<pre>
<foaf:Person>
<foaf:holdsAccount>
<foaf:OnlineAccount>
<foaf:accountServiceHomepage rdf:resource="http://flickr.com"/>
<foaf:accountName>ldodds</foaf:accountName>
</foaf:OnlineAccount>
</foaf:holdsAccount>
</foaf:Person>
</pre>

The above describes that the person has an account, identified as "ldodds", on the service that is (indirectly) identified via an accountServiceHomepage property. Or more plainly: this person has an account "ldodds" on flickr.com.

Most services produce a custom homepage for their user, but currently there's no way to state this in FOAF, nor infer it from the currently available property.

The proposal is to add a new property: foaf:accountHomepage. This would indicate the homepage associated with a given foaf:accountName.
E.g.:

<pre>
<foaf:Person>
<foaf:holdsAccount>
<foaf:OnlineAccount>
<foaf:accountServiceHomepage rdf:resource="http://flickr.com"/>
<foaf:accountName>ldodds</foaf:accountName>
<foaf:accountHomepage rdf:resource="http://flickr.com/people/ldodds/"/>
</foaf:OnlineAccount>
</foaf:holdsAccount>
</foaf:Person>
</pre>

foaf:accountHomepage could also be safely declared as an Inverse-Functional-Property (IFP), allowing OnlineAccount resources to be safely merged together. It's not safe to make accountName an IFP as the value-space for that property is defined relative to the service its associated with.
[[Category:Vocabulary_Issues]]

NameVocabIssue

2007-11-01T01:37:18Z

Admin: Automated import of articles

NameVocabIssue

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

Current status: open, with proposed resolution at NamesInFoaf (pointers there to where intially raised, discussions etc.)

Owner: mof-rdf@mfd-consult.dk

Summary:
''...it turns out that the concepts of "first name", "last name" and even "family name" apply to only a small subset of the worlds population, and even within cultures with those notions there are exceptions to the rules, e.g. the Danish royal family that only has first names.'' (NamesInFoaf)

Proposed solution:
''Let's keep foaf:name, dump the rest of the existing name-related properties, and create a new set of classes for sortable and searchable personal names, suitable for world-wide deployment.'' [in a new namespace?]

see also [http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012506.html Morbus's email to rdfweb-dev]

I've outlined another way to approach this issue in NamesInFoafAlternate -- IanDavis

----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

MissingXmlBaseIssue

2007-11-01T01:37:06Z

Admin: Automated import of articles

''current status: open''. This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

'''Problem''': The FOAF RDFS file can be fetched from http://xmlns.com/foaf/0.1/index.rdf . (It can also be fetched from the same URL without the index.rdf, when using content negotiation.) The RDFS document contains an owl:Ontology element that is supposed to describe the document itself. Its URI is given as http://xmlns.com/foaf/0.1/ . This does not match the document's URL. An RDF processor cannot tell that the element is supposed to describe the current file.

'''Solution''': Add an xml:base="http://xmlns.com/foaf/0.1/" declaration. This tells RDF processors to use that URI instead of the file's URL for all RDF purposes, removing the mismatch.

'''Discussion''': Thread at http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013678.html

(Summary: RichardCyganiak thinks this is a problem because it could break ontology editors and viewers. BenjaminNowack, DanBrickley and DavidMenendez disagree and say that this is not a problem. But consensus seems to be that adding the xml:base wouldn't hurt either. Dan says he's going to add it in a future site update: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013690.html)

-- RichardCyganiak
[[Category:Vocabulary_Issues]]

MemberVocabIssue

2007-11-01T01:36:54Z

Admin: Automated import of articles

MemberVocabIssue

Current status: open
Owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

[http://rdfweb.org/pipermail/rdfweb-dev/2003-December/012257.html mail to rdfweb-dev]

This issue is also described in "PointingFromPersonToGroup."

----

Each BlahBlahIssue page can be created from the IssueTemplate; you can delete the general guidelines and replace them with content as seems appropriate.

Broadly, each issue description should:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

MboxSha1SumCaseIssue

2007-11-01T01:36:42Z

Admin: Automated import of articles

-
MboxSha1SumCaseIssue

current status: open

Currently when various tools convert foaf:mbox rdf:resource mailto's into foaf:mbox_sha1sum, the email is not canonisized by making it lower case. This is required for RFC 822 "Standard for the format of ARPA internet text messages" in the section 3.4.7 "Case Independence".

''However, the current [http://xmlns.com/foaf/0.1/#term_mbox_sha1sum spec text for foaf:mbox_sha1sum] states that it is ''a textual representation of the result of applying the SHA1 mathematical functional to a 'mailto:' identifier (URI) for an Internet mailbox that they stand in a foaf:mbox relationship to''. So, if something's wrong, it is really the [http://xmlns.com/foaf/0.1/#term_mbox foaf:mbox property spec text] that should be updated.'' -- MortenFrederiksen

As an example:
<pre>
<foaf:mbox rdf:resource="mailto:christophera@alacritymanagement.com"/>
</pre>
converts to:
<pre>
<foaf:mbox_sha1sum>9ee1c03552f22e89592ce583be0ab8db0c4f2c59</foaf:mbox_sha1sum>
</pre>
However:
<pre>
<foaf:mbox rdf:resource="mailto:ChristopherA@AlacrityManagement.com"/>
</pre>
converts to:
<pre>
<foaf:mbox_sha1sum>6106154de50a65491d1316322f674c27d054ee66</foaf:mbox_sha1sum>
</pre>

''Another thing is that RFC 822 states that the local part is case sensitive, so it's really only the host name that could/should be lowercased.'' -- MortenFrederiksen
[[Category:Vocabulary_Issues]]

KnowsAgentVocabIssue

2007-11-01T01:36:30Z

Admin: Automated import of articles

KnowsAgentVocabIssue

Current status: open

Owner: jim@jibbering.com or danbri@rdfweb.org ?

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

''"Michael Bauser" <michael at bauser.com>

> If TypePad is going to have a usable UI, they need to admit that users

> want non-persons on their blogrolls, replace the "People" lists with

> "Blogroll", *and* make users answer the yes/no question "Is this link

> for an individual or not?" every time they add a link. *Then* you've got

> a UI that accomplishes what the users want *and* labels the data in a

> way that developers can use it to create good FOAF.

IMO, switching foaf:Person to foaf:Agent in such RDF would be sufficient,
the fact that (somebody ie a subject) is a Person (ie they have an rdf:type
foaf:Person) is often not essential, and generally can be found from more
definitive sources than a foaf file that refers to them. It's safe, okay we
don't know they know a Person unless we have more info from other files, but
that's often the case anyway.

Jim.''

[http://www.rdfweb.org/pipermail/rdfweb-dev/2004-January/012435.html mail from Jim ley to rdfweb-dev]

see also

[http://rdfweb.org/pipermail/rdfweb-dev/2004-January/thread.html#12263 knows range thread, Jan 2004]

[http://rdfweb.org/pipermail/rdfweb-dev/2004-January/thread.html#12326 typepad thread, Jan 2004]

[http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012536.html Victor's message, Jan 2004 ;)]
----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

IssueTemplate

2007-11-01T01:36:17Z

Admin: Automated import of articles

BlahBlahIssue

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

Each BlahBlahIssue page can be created from the IssueTemplate; you can delete the general guidelines and replace them with content as seems appropriate.

Broadly, each issue description should:

* have pointers to rdfweb-dev email, IRC chatlog, weblog etc. pages where the issue was originally raised
* briefly summarise the problem, oportunity, confusion etc.
* link to test cases, examples etc where possible
* have an issue owner (who has acknowledged this role in some archived forum)

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

InverseOfThumbnailIssue

2007-11-01T01:36:07Z

Admin: Automated import of articles

It would be nice for the FOAF vocabulary to include an inverse property of ''foaf:thumbnail''.

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

* [http://rdfweb.org/pipermail/rdfweb-dev/2004-January/012523.html Mail from Morten Frederiksen to rdfweb-dev]

= Example =
An RSS channel referencing a web-sized image that has a thumbnail as well as an original version and a page showing the image, with a link to the original.
<pre>
...
<rss:channel rdf:about="http://example.com/gallery/index.rdf">
...
<rss:items>
<rdf:Seq>
<rdf:li rdf:resource="http://example.com/gallery/image.jpg"/>
</rdf:Seq>
</rss:items>
</rss:channel>
<rss:item rdf:about="http://example.com/gallery/image.jpg">
<rdf:type rdf:resource="http://xmlns.com/foaf/0.1/Image"/>
<rss:title>Example image</rss:title>
<rss:link>http://example.com/gallery/image.html</rss:link>
<foaf:page rdf:resource="http://example.com/gallery/image.html"/>
<foaf:thumbnail rdf:resource="http://example.com/gallery/image.thumb.jpg"/>
<foaf:original rdf:resource="http://example.com/gallery/image.original.jpg"/>
</rss:item>
...
</pre>
[[Category:Vocabulary_Issues]]

HashSlashIssue

2007-11-01T01:35:52Z

Admin: Automated import of articles

HashSlashIssue

Current status: open

Owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

----

''FOAF currently names classes and properties with URIs such as:
- http://xmlns.com/foaf/0.1/workplaceHomepage

An alternate design would be something like:
- http://xmlns.com/foaf/0.1/#workplaceHomepage

Each FOAF term (ie. class, property) is a thing with an http:* URI as its name,
without indirecting via the '#' fragment mechanism.

Context: the current FOAF design was itself motivated by concern about ns URIs
that end in '#', since the denotation of URIs of the form
http://example.com/something#somethingelse was complicated by mention of content
negotation and context dependence in the URI spec (RFC2396).

Further discussion on what HTTP URIs name from TimBL in
http://www.w3.org/DesignIssues/HTTP-URI

This issue tracker is for gathering evidence about the severity of the problem,
if indeed it is a problem. Some claim that properties and 'http documents' are
dijoint, ie. that nothing can be both an http document. FOAF can be seen as
contradicting that.

Note also that FOAF's approach to this design choice is shared with the Wordnet
vocabulary deployed at http://xmlns.com/wordnet/1.6/
(eg. classes such as http://xmlns.com/wordnet/1.6/Car), the Dublin Core
vocabulary at http://purl.org/dc/elements/1.1/ (eg. properties such as
http://purl.org/dc/elements/1.1/), as well as the preceding DC 1.0; also RSS 1.0
(http://purl.org/rss/1.0/ eg http://purl.org/rss/1.0/link) and some namespaces
associated with Adobe's XMP system (deployed in Photoshop 7, PDF tools etc).
Also Creative Commons rights metadata, see spec at
http://www.creative-commons.org/metadata/spec using vocab named
http://web.resource.org/cc/, classes with names like
http://web.resource.org/cc/Work.

The W3C Technical Advisory Group(TAG) has an issue tracking a generalisation of
this point: http://www.w3.org/2001/tag/ilist#httpRange-14 "What is the range of
the HTTP dereference function?".

DC, RSS, Adobe XML, Creative Commons and FOAF when collected together account
for a fair slice of all the RDF out there in the Web. If something's wrong,
we will need some migration strategies that strike a balance between doing the
right thing and preserving people's existing investment in these RDF apps.

I would also like more information about the class of things that can supposedly
be named with HTTP names. What inferences can we draw when we see a URI that
begins http: and doesn't contain a '#'? What things are true of all such resources?

Example:

- http-named things are not spatial things, they have no location in space and time
- hmm, same goes for RDF classes and properties
- ...''

[http://www.rdfweb.org/pipermail/rdfweb-issue-archive/2003-March/000037.html rdfweb issue list entry]

----

Other information

[http://www.w3.org/2001/03/identification-problem/ Sandro Hawke has a substantial writeup]; I also found a [http://lists.w3.org/Archives/Public/www-archive/2001Nov/0083.html message from Sean Palmer] on www-archive and [http://esw.w3.org/topic/HashVsSlash Hash vs Slash on the ESW wiki] and [http://esw.w3.org/topic/OverloadedUri OverloadedUri].

''A HashURI is a URI with a hash mark ("#") in it (technically, a URI with a fragment identifier), specifically one used to denote something which is not a traditional web page.

Use of HashURIs is intended to help WhenBrowsableAndUnambiguousCollide. It is often presented in contrast to SlashURI, via the debate HashVsSlash.

The idea is to use URIs like

http://www.w3.org/1999/02/22-rdf-syntax-ns#type

to combine

(document URI) # (term introduced in the document)

This works well for a lot of RDF content. It's very natural (especially with rdf:ID) to introduce a new conceptual thing and name it with the same action.

Web retrieval does approximately the right thing. When you ask for foo#bar, your client asks for a representation of foo and then (depending on the content-type of the result) may try to find something named bar in that result.'' (from [http://esw.w3.org/topic/HashURI HashURI on the ESW wiki])

----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

EstablishRoadMap

2007-11-01T01:35:40Z

Admin: Automated import of articles

Road Map:

'''Attribution:''' Below design considerations/steps derived from [http://reliant.teknowledge.com/RKF/publication/Stanford/Ontology%20Tutorial.htm Ontology Development 101: A Guide to Creating Your First Ontology].

'''Design Considerations'''

1) There is no one correct way to model a domain — there are always viable alternatives. The best solution almost always depends on the application that you have in mind and the extensions that you anticipate.

2) Ontology development is necessarily an iterative process.

3) Concepts in the ontology should be close to objects (physical or logical) and relationships in your domain of interest. These are most likely to be nouns (objects) or verbs (relationships) in sentences that describe your domain.

'''Design Steps'''

Step 1. Determine the domain and scope of the ontology

We suggest starting the development of an ontology by defining its domain and scope. That is, answer several basic questions:

· What is the domain that the ontology will cover?

· For what we are going to use the ontology?

· For what types of questions the information in the ontology should provide answers?

· Who will use and maintain the ontology?

Step 2. Consider reusing existing ontologies

Step 3. Enumerate important terms in the ontology

Step 4. Define the classes and the class hierarchy

Step 5. Define the properties of classes-slots

Step 6. Define the facets of the slots

Slots can have different facets describing the value type, allowed values, the number of the values (cardinality), and other features of the values the slot can take.

Step 7. Create instances
[[Category:Vocabulary_Issues]]

DocumentIssue

2007-11-01T01:35:27Z

Admin: Automated import of articles

DocumentIssue
FoafVocab

Current status: open, not assigned

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

== General issue ==

From the current term definition for foaf:Document:

''We do not (currently) distinguish precisely between physical and electronic documents, or between copies of a work and the abstraction those copies embody. The relationship between documents and their byte-stream representation needs clarification (see foaf:sha1 for related issues).''

The missing disinction between physical and eletronic documents makes expectations hard to meet.

See also [http://www.ilrt.bris.ac.uk/discovery/chatlogs/rdfig/2004-10-08.html#T21-18-48 #rdfig discussion re "linking" to urn:isbn].

-----
When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

DataSources 2fexpire 2emdb

2007-11-01T01:35:17Z

Admin: Automated import of articles

ChatVocabIssue

2007-11-01T01:35:04Z

Admin: Automated import of articles

ChatVocabIssue

Current status: open
Owner: danbri at rdfweb.org (from IssueTracker page)

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

Issue description - rdfweb-dev mail from danbri: [http://www.rdfweb.org/pipermail/rdfweb-dev/2003-July/011364.html foaf:chat sub-properties could be better described]

''<danbri> We were discussing the kinds of things which properties such as
foaf:msnChatID can apply to...
It was tempting to say foaf:Person, however bots, scripts and other software
artifacts can have chat IDs...

<kota> what about chatID, simply?

<danbri> foaf:nick serves that purpose, largely

<danbri> but without scoping a chat ID to a particular controlled set of names,
you lose a lot of power

<kota> hmm

<kota> i see

<danbri> If I say 'there is a person and they have a chat id of danbri_2002' that
doesn't unambiguously identify anything for sure.

<danbri> If I say 'there is a person with a foaf:aimChatID of 'danbri_2002', that
picks out... me.

<danbri> ...which is good foaf, as it makes yet another way of merging data
together... ''

[http://ilrt.org/discovery/chatlogs/foaf/2003-07-06#T11-04-37 IRC chat 2003-07-06], quoted in [http://www.rdfweb.org/pipermail/rdfweb-issue-archive/2003-July/000060.html rdfweb-de issue archives]

''What is their domain? range? Are they owl:InverseFunctionalProperty?

There are some possible variations here.

Jabber IDs get used for all sorts of things. There is also a Jabber URI scheme
we should look at.

The others, it is tempting to say they have an rdfs:domain of Person. However we
often see IM accounts for bots and other non-humans.

This suggests that an Agent class may be appropriate. (MCF had this btw).'' [http://www.rdfweb.org/pipermail/rdfweb-issue-archive/2003-July/000059.html bug description on rdfweb-dev issue archive]

----

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

ChatIdSubPropertiesIssue

2007-11-01T01:34:51Z

Admin: Automated import of articles

ChatIdSubPropertiesIssue

current status: open
owner: danbri@rdfweb.org

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

foaf:chat sub-properties could be better described

''What is their domain? range? Are they owl:InverseFunctionalProperty?

There are some possible variations here.

Jabber IDs get used for all sorts of things. There is also a Jabber URI scheme
we should look at.

The others, it is tempting to say they have an rdfs:domain of Person. However we
often see IM accounts for bots and other non-humans.

This suggests that an Agent class may be appropriate. (MCF had this btw).''

from [http://rdfweb.org/pipermail/rdfweb-issue-archive/2003-July/000059.html rdfweb-issue mail]

[http://rdfweb.org/pipermail/rdfweb-dev/2003-July/011364.html chatids, July 2003, rdfweb-dev, danbri]

[http://rdfweb.org/pipermail/rdfweb-dev/2003-July/011486.html describing chat channels - Jul 2003, rdfweb-dev, danbri]

JabFoaf wiki page

[http://rdfweb.org/pipermail/rdfweb-dev/2003-August/011549.html IM urls, Aug 2003, Ian Davis, rdfweb-dev]

[[Category:Vocabulary_Issues]]

BlahBlahIssue

2007-11-01T01:34:38Z

Admin: Automated import of articles

This is an example issue, documentation is basically freeform wiki notes, but take care to link back to the IssueTracker page so we can find all the issues mechanically.
[[Category:Vocabulary_Issues]]

BirthdayIssue

2007-11-01T01:34:24Z

Admin: Automated import of articles

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.
* Status: Active ([http://rdfweb.org/pipermail/rdfweb-dev/2005-March/013958.html discussion on rdfweb-dev])
* Owner: mortenf

== Summary ==

For somewhat obvious social reasons, it would be nice to have a property that somehow gave indication of the age, birthday and/or birthdate of a person, first and foremost for birthday reminders. The origin of this issue is unclear, but at least Danny Ayers has suggested it in a [http://rdfweb.org/pipermail/rdfweb-dev/2003-November/012186.html mail to rdfweb-dev], with earlier [http://rdfweb.org/pipermail/rdfweb-dev/2003-August/011631.html mentions by danbri on rdfweb-dev] and a later [http://rdfweb.org/pipermail/rdfweb-dev/2004-August/013566.html resurrection by Adam Atlas] as well as [http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013733.html an action follow-up by Libby].

== Problems ==

Some want to express the exact date and time of their birth, some don't want to give out their age, some don't mind other people knowing their approximate age but don't want to receive birthday greetings...

At the same time there might be security reasons to think about, as semantic bots may soon be able to know your mothers birthday.

When thinking about the different options, it might be wise to also consider the microparsing issue -- whether it is easy to locate an exact date or easy to locate e.g. all dates with a given year, month, or day (or a combination thereof).

== Usage history ==

[http://rdfweb.org/people/danbri/rdfweb/danbri-foaf.rdf danbri's original FOAF file] uses ''foaf:dateOfBirth''.

LiveJournal exposes information with ''foaf:dateOfBirth''.

== Options ==

''This option list is mostly gleaned from [http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013733.html Libby's mail].''

OneProp:: The simplest possible solution would be just one predicate, ''foaf:dateOfBirth'' (or foaf:birthday, but that doesn't seem to be in use anywhere, and could be confused with the yearly recurring event), containg a regular [http://www.w3.org/TR/NOTE-datetime W3CDTF date] ('''yyyy-mm-dd'''). This approach is also used by Paul Ford in his [http://www.xml.com/pub/a/2004/09/01/hack-congress.html Hacking Congress] column ([http://www.xml.com/2004/09/01/examples/Politics.rdf schema]), even if the date notation isn't W3CDTF. This approach is simple, but doesn't giver users much to choose from, and makes it hard(er) to query for e.g. birthdays next month or tomorrow (generally, usually you know the date of tomorrow).

OnePropBis:: A variation on the date format for a single property is to allow an arbitrary [http://hydracen.com/dx/iso8601.htm ISO8601] date, as [http://rdfweb.org/pipermail/rdfweb-dev/2003-August/011642.html suggested by Ian Davis]: ''ISO8601 lets you miss out a year by replacing it with a dash: <pre><foaf:birthday>--06-15</foaf:birthday></pre> Looks a bit cryptic though.'' This approach is flexible for producers, but puts a burden on consumers, that need to handle many different formats.

TwoProp:: Another option is just two non-overlapping properties as [http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013740.html suggested by Richard Cyganiak], one with only the year ('''yyyy''') and one with month and day ('''mm-dd'''). This option makes it possible to cater for the no-age camp as well as the no-presents camp, at the cost of a more complicated query when you want the combination.

TwoPropBis:: A variation on the theme of two properties is the one [http://rdfweb.org/pipermail/rdfweb-dev/2004-August/013581.html suggested by Bill Kearney]: Two properties, one with a complete date ('''yyyy-mm-dd'''), one with just month and day ('''mm-dd'''). This approach keeps the simple approach, and adds a predicate for those wishing to hide their age, again at the consumers disadvantage.

TwoPropSplit:: As [http://rdfweb.org/pipermail/rdfweb-dev/2005-March/013960.html suggested by Ian Davis], this is essentially the same as TwoPropBis, with the two properties being split (evenly!) between FOAF and the [http://vocab.org/bio/0.1/ bio vocabulary]: A new property ''foaf:birthday'' ('''mm-dd''') and the existing ''bio:date'' ('''yyyy-mm-dd''') used with ''bio:Birth''. This option seems to hit a sweet spot, catering for most use cases, including giving the option of just supplying a year, since the ''bio:date'' property is based on ISO8601. The only potential use case not covered is a simple query for birthdays in a specific month, as [http://rdfweb.org/pipermail/rdfweb-dev/2005-March/013964.html pointed out by Benjamin Nowack].

ThreeProp:: Yet another option is three separate datatyped properties as [http://rdfweb.org/pipermail/rdfweb-dev/2004-August/013585.html suggested by Benjamin Nowack], one with the year ('''yyyy'''), one with the month ('''mm'''), and one with the day ('''dd'''). There might be a problem with using the datatypes, since relevant day type (''xsd:gDay'') suggests monthly recurrence, not yearly, as per [http://www.w3.org/TR/xmlschema-2/#gDay XML Schema Part 2]: ''gDay is a gregorian day that recurs, specifically a day of the month such as the 5th of the month. Arbitrary recurring days are not supported by this datatype. The ·value space· of gDay is the space of a set of calendar dates as defined in § 3 of [ISO 8601]. Specifically, it is a set of one-day long, monthly periodic instances.'' Without the datatyping, this option is the most flexible and at the same time still somewhat easy to consume, even if it does require a more complicated query for the combination.

Bio:: The [http://vocab.org/bio/0.1/ bio vocabulary] could be used instead. The date (or recurrence) still needs to be expressed, but the burden would then be on the bio maintainer. This options basically sidesteps the issue (although it's actually OneProp in another vocabulary, using '''yyyy-mm-dd'''), but one advantage would be the fact that there would not be a need for yet another property indicating place of birth, as that is integrated into the bio vocabulary.

iCal:: RDF/iCal might be an option, but the same datatype problems as with the ThreeProp options exist. Also, iCal demands that all parts of the date are indicated -- essentially an iCal-version of OneProp with iCal support ('''yyyy-mm-dd''').

=== Potential Actions for TwoPropSplit ===

* A new property ''foaf:birthday'' is added to the FOAF vocabulary.
* Accompanying term documentation is written (see also [http://xmlns.com/foaf/doc/ existing term documentation]).
* An FAQ-style weblog post is written, including examples and pointers to the bio vocabulary.
* "Migration" of existing usage.

==== New property: foaf:birthday ====

<pre>
<rdf:Property rdf:about="http://xmlns.com/foaf/0.1/birthday"
vs:term_status="testing"
rdfs:label="birthday"
rdfs:comment="The month and day of the birth of something, in "mm-dd" form.">
<rdfs:domain rdf:resource="http://www.w3.org/2000/01/rdf-schema#Resource"/>
<rdfs:range rdf:resource="http://www.w3.org/2000/01/rdf-schema#Literal"/>
<rdfs:isDefinedBy rdf:resource="http://xmlns.com/foaf/0.1/"/>
</rdf:Property>
</pre>
Notes:
* The domain is ''rdfs:Resource'', as there doesn't seem to be any point in limiting birthdays to people or even agents - bots, pets and projects can have them as well. On the other hand, the bio vocabulary limits events to just people...
* This could be declared as an ''owl:DatatypeProperty'', but the OwlClassFoafSpecIssue (which could cover properties as well) is still open.

==== Term Documentation for foaf:birthday ====

<p>
The <code>foaf:birthday</code> property relates something, e.g. a <code>foaf:Person</code>, to a string representing the month and day of its birth in "mm-dd" form.
</p>

<div class="example">
<pre><foaf:Person>
<foaf:name>Jim Ley</foaf:name>
<foaf:birthday>12-31</foaf:birthday>
</foaf:Person>
</pre>
</div>

<p>
It is also possible to express a persons precise date of birth by using the terms <code>bio:event</code>, <code>bio:Birth</code>, and <code>bio:date</code> from the <a href="http://vocab.org/bio/0.1/">bio vocabulary</a>:
</p>

<div class="example">
<pre><foaf:Person>
<foaf:name>Jim Ley</foaf:name>
<bio:event>
<bio:Birth>
<bio:date>1999-12-31</bio:date>
</bio:Birth>
</bio:event>
</foaf:Person>
</pre>
</div>

<p class="editorial">
Note that there may be security issues with making birthdays and/or birthdates public. Sometimes this type of information can be used for identity theft.
</p>

<p class="history">
This term was added at ... discussion ... decision ... meeting ... history documented in the wiki page <a href="http://rdfweb.org/topic/BirthdayIssue">BirthdayIssue</a>...
</p>

==== Weblog post: The property foaf:birthday ====

As the term documentation, with the addition of some thoughts regarding the other options?

==== Migration strategy ====

* Step 1: Bug danbri to fix his file.
* Step 2: Hunt down other people using ''foaf:dateOfBirth'' and get them to change.
* Step 3: Determine current status of LiveJournal development and try to push the "upgrade" (hopefully including other improvements as suggested by crschmidt). Update 2005-03-15: [http://www.livejournal.com/community/lj_dev/675451.html work is being done]!
[[Category:Vocabulary_Issues]]

AccountServiceIssue

2007-11-01T01:34:11Z

Admin: Automated import of articles

AccountServiceIssue

current status: open

This is a FoafVocab issue, documented as such by linking it from the IssueTracker page.

On the Jabber network, we might want to create FOAF representations for things like chatrooms, bots, and IM servers. In particular, currently many Jabber servers have their own vCards and we would want to replace those with a FOAF representation. I think that an IM server is a kind of Agent that is not yet discussed elsewhere, which I would characterize as an AccountService. This terms needs further definition but I think it captures the core idea (related, naturally, to the existing accountServiceHomepage property).

Originally described here: http://www.saint-andre.com/blog/2004-09.html#2004-09-17T09:25

See also: http://rdfweb.org/pipermail/rdfweb-dev/2004-September/013693.html

Issue owner: Peter Saint-Andre

TODO:

* proposed markup
* test cases
* examples

When an issue is resolved or its status w.r.t. the FOAF spec changes, that changed state of affairs should be documented somewhere less transient than the wiki. See IssueTracker for more notes on issue management conventions.
[[Category:Vocabulary_Issues]]

Tools~

2007-11-01T01:33:08Z

Admin: Automated import of articles

FoaF Creators

* Create a FoaF file with [[LeighDodds]]' [http://www.ldodds.com/foaf/foaf-a-matic FOAF-a-matic]
* or [http://www.formsplayer.com/demo/foaf/foaf-creator.html FoaF Creator], which uses [http://www.formsPlayer.com/ formsPlayer] and [http://www.w3.org/TR/xforms XForms].
* [http://www.foafme.com foafme] as a swing gui to to roundtrip editing and Jena backend.
* [http://www.urbigene.com/foaf/ scifoaf] a java webstart application using the [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi PubMed] bibliographic database.
* Elmo is a Java API for FOAF available at [http://www.openrdf.org/ openrdf.org]
* [http://www.videntity.org/ vIdentity] creates FOAF, ([http://lionkimbro.videntity.org/foaf.xml example,]) though it's limited in what you can express.
* [http://dowhatimean.net/2006/08/exporting-the-os-x-address-book-to-foaf Export Address Book to FOAF] is an AppleScript for Mac OS X that allows users to manage their FOAF profile from within the Address Book.

Using FOAF for authentication in webapps:

* [http://www.sharedid.com/ SharedID: Single Sign On via FOAF]

Aggregators, user interfaces, visualization systems etc... let's collect links first, reorganise as we go...

* A FoafWebBrowser like PeopleLink or FoafExplorer lets you see people's FOAF pages by a web interface.
* FoafNaut lets you view FOAF pages by SVG.
* [http://www.zopto.com/ Zopto: Foaf community]
* [http://eikeon.com/foaf/ eikeon's FOAF: Web View]
* [http://www.openrdf.org/ Elmo] contains a set of tools for crawling, smushing and validating FOAF profiles
* [http://www.urbigene.com/foafexplorer/ myfoafexplorer] java 1.5 applet used to browse a scientific network (papers, groups,...) based on FOAF
* [http://thenowhereman.com/foaf/ FOAF-inator] is a FOAF navigation tool developed in PHP.
* [http://foafmap.net FOAFMap]: Display FOAF profiles (groups and personnal) on a Google Map
* Other CoolStuff
* ...others

''What user-oriented software packages are exploring FOAF support?''

* does [http://www.foafnaut.org/ FOAFNaut] count? It's software, but it's a webpage, it's an SVG and Javascript webpage application thingumy, ...
* [http://usefulinc.com/foaf/foafbot foafbot] will chat to users in an IRC channel, recounting things it has learned from reading the Web of FOAF documents.
* [http://www.usercreations.com/spring/ Spring] v1.3+ has some [http://www.usercreations.com/weblog/2003/05/19.html#a223 FOAF support] (see [http://rdfweb.org/mt/foaflog/archives/000031.html foaf weblog] for detail).
* [http://www.brindys.com/winrss/ WinRSS] has support for FOAF (through connecting to [http://xml.mfd-consult.dk/foaf/explorer/ FoaF Explorer]).
* [http://www15.brinkster.com/semaview/default.aspx]An interesting application of the semantic web which brings together an Office XP addin to publish your contacts in RDF format to a webservice which then forms communities based on your friends.
* [http://www15.brinkster.com/semaview/foaf.aspx] A simple FOAF generator.
* [http://james.seng.cc/wiki/wiki.cgi?PonG PonG DAML] - A tool to keep your address book up to date (via XMLRPC) and generates foaf.
* [http://www.onespeeddave.com/foaf_tools.tar.gz] Bourne shell scripts for maintaining and generating foaf.
* [http://www.emacswiki.org/cgi-bin/alex/FoafMap FoafGeoGraph] Perl script to extract geo information from FOAF files and plot them using xplanet. Shows how to use XML::FOAF for the simple things such as the name, and how to use RDF::Core::Statement to get at more than one seeAlso and the geo:lat and geo:long inside the foaf:based_near (as well as fetching foaf files from the web).
* [http://www.ahsonline.com.au/dod/FoafViewerPlugin.zip] PHPWiki Basic Foaf Profile Viewer - in progress, part of wider effort to Foaf Enable applications like PHPwiki, phpbb, phplist etc. Similar to SharedID.
* [http://www.codewitch.org/twiki/bin/view/Main/MTFOAF] Basic Foaf plugin for Movable Type - in progress, uses XML::Foaf to give access to FOAF data from Movable Type templates
* [http://flink.semanticweb.org Flink] is a dynamic presentation of the social network of the Semantic Web community, extracted from webpages, publications, emails and FOAF profiles. Flink also exports the aggregated data in FOAF format.
[[Category:TechAndSoftware]]

Tools

2007-11-01T01:32:55Z

Admin: Automated import of articles

TinyCrapScutter

2007-11-01T01:32:41Z

Admin: Automated import of articles

Here is an example of a tiny, but very poorly designed, RDF scutter.

see also: [[Scutter]], ScutterSpec

It is crap because...

* doesn't use robots.txt, etags, last-modified
* doesn't use a real rdf parser
* doesn't do much with the data it finds
* doesn't pause before re-requesting a page

See Julian Bond's [http://www.voidstar.com/node.php?id=1474 On writing spiders and scutters for FOAF] for an excellent writeup of the issues involved in doing this properly.

It is interesting because:

* it is a quick and nasty way to show that there is a web of rdf data out there
* the out.html file it writes shows what a bunch of these RDF-described people look like

'''It is probably OK to run this on occasion, since its parser is so poor it is rarely likely to find its way through more than a few dozen files before running out. Don't leave it running unattended...'''

<pre>
#!/usr/bin/env perl
use LWP::Simple; # Worst FOAF Scutter Ever - for demos only # danbri@rdfweb.org
my $start=shift || 'http://rdfweb.org/people/danbri/rdfweb/danbri-foaf.rdf';
my %seen,%seealso,$out,%seenpic;$seealso{$start}=1;my $of="out.html";while(1)
{
my @left=();foreach my $k(sort keys %seealso){push(@left, $k) if(!$seen{$k})};
print "stack todo: ".join(' ',@left)."\n";die "Done. Bye!" if scalar @left==0;
my $todo=pop @left;print "fetching: $todo\n";$page=get $todo; $seen{$todo}++;
while($page =~ s!rdfs:seeAlso\srdf:resource="([^]]+)"\s*/>!gl($1,$todo)!e) {};
sub gl{my $more=shift;my $p=shift; print "link found seeAlso: $more via $p\n";
if (!$seen{$more}) { $seealso{$more}++;} return ''; }
while($page =~ s!depiction\s+rdf:resource="([^]]+)"\s*/>!gp($1,$todo)!e){};
while($page =~ s!img\s+rdf:resource="([^]]+)"\s*/>!gp($1,$todo)!e){}; sub gp {
my $p = shift; my $u = shift; return '' if $p =~ m/mpg/i; return '' if $p =~
m/svg/i;if(!$seenpic{$p}){$out .= "<img src='$p' width='128' height='128'/>\n";
}$seenpic{$p}++; return '';}open (OUT,">$of")|| die "failed: $of"; print OUT
"<html><head><title>all your foaf...</title></head>\n<body>\n";
print OUT $out; print OUT "</body></html>\n\n"; close OUT;
}

</pre>
[[Category:TechAndSoftware]]