ShortFAQ
From FOAF
[edit] The FOAF FAQ
Setup a ShortFaq in prep for addition to new website.
[edit] Background
[edit] What is FOAF?
FOAF, or 'Friend of a Friend' provides a way to create machine-readable homepages in the Web. Technically, it is an RDF/XML 'Semantic Web' vocabulary. FOAF documents are most commonly used as a way of representing information about people in a way that is easily processed, merged and aggregated.
FOAF provides conventions for saying the sorts of things that you might say in your homepage in a way that is easy for computers to process. Since computers are pretty dumb, and can't read human languages, we provide simplistic FOAF descriptions, to help them understand the data they see. FOAF is a 'Semantic Web' project, which is an effort to make the Web easier for machines to help us navigate.
[edit] Where can I find out more?
The best resource is the FOAF Website, which is geared towards providing all the information you'll need to create a FOAF file for yourself, or to implement creation of programmatic FOAF for your website. Whether it be personal or professional, the FOAF project aims to solve the question of how to represent data in RDF.
[edit] How can FOAF help with spam?
We provide a way to represent a 'hashed' email address in FOAF, 'foaf:mbox_sha1sum'. If you know the original, you can figure out the sha1sum but not vice versa. This means people can be identified without obviously revealing their email address, making it harder for spammers to harvest addresses from FOAF data.
The FOAF whitelists experiment takes this a step further, exploring the use of FOAF for sharing lists of non-spammer mailboxes, to aid in collaborative mail filtering tools.
[edit] Creating FOAF
[edit] Why should I create a FOAF document?
By describing yourself using FOAF you're providing information, in a machine-processable format, about yourself, your interests, your location, and your friends. And this isn't a comprehensive list!.
There are many existing and developing applications that can take this information and use it in many interests ways. The could include email "whitelists" that will allow you to prune out SPAM messages from people you don't know; business oriented applications that can leverage a network of business contacts; social network tools; and a whole host of others.
If you're familiar with 'blogging and providing RSS syndication of the content of your 'blog, then one way to view FOAF is as syndicating yourself. FOAF has the potential to drive innovation for all kinds of applications just as RSS has done so for publishing.
[edit] How do I create my first FOAF document?
At present the simplest way to create your first FOAF file is to visit the FOAF-a-Matic and fill out the forms provided. The tool will generate a basic description for you that covers the most commonly used FOAF data items, i.e. who you are and who your friends are.
The FOAF-a-Matic will generate the FOAF document for you, but you should then cut-and-paste this from the online form into a file that you then save/upload to your website. This FAQ can't possibly cover all the many different ways to do this, but it's worth mentioning that many 'blogging tools have a way to upload additional files directly to your website.
However if you're a happy RDF or XML hacker then you may want to pitch right in and craft your FOAF document yourself. If so, then you may want to work through the examples listed in the wiki.
[edit] What URL should I use for my FOAF document? Where should it live on my web site?
You can place the file anywhere. The only requirement being that it be on the public internet. If you can download the file through your browser then you're all set. Typically, FOAF files carry an extension of ".rdf", so that your web server can understand what type of content is in the file.
[edit] How can I tell my FOAF file is correct?
For the moment there's no special "FOAF Validator", however you can use the W3C RDF Validator service to check your FOAF file. However, the FoaF Explorer provides some visual feedback for a subset of valid files, but should not be expected to handle all cases.
If you want to use the W3C RDF Validator, then here's how you do it:
If you haven't yet uploaded your FOAF document to the web, then simple paste in the RDF into the form provided and click "Parse RDF".
If your FOAF file is on the web then you can enter the URL in the text box below the form, and then click "Parse URI".
(You can ignore the other options for now, unless you're interested in exploring the RDF data further.)
The validator will then validate the RDF (however it was provided) and provide you with a summary page that has a great deal of information on it, including the original source document, details about what RDF statements it's extracted, and a pretty graph of the results. Most importantly though it includes the validation feedback, you can jump to this directly using the "Feedback" link at the top of the page.
If your FOAF file is valid then you should see this message: Your RDF document validated successfully.
If your FOAF file is invalid then you will see some error messages describing the problems. If you have trouble interpreting these then feel free to post to the rdfweb-dev mailing list, or drop into the #foaf IRC channel for help.
For a more technical discussion on the detection of certain kinds of mistake in FOAF files, see information on contradictions in FOAF.
[edit] How should I link to my FOAF file?
For information on this see our other page on how to link up your FOAF file.
[edit] I've updated my FOAF file is there anything I should do?
Generally speaking no, the next time your FOAF document is picked up by a FOAF harvester the new data will be processed. And anyone using tools like FoaF Explorer will see the results immediately. Depending on the tool you use, data may be cached to save system resources on one end oranother.
Note: if you are a journalist considering writing a piece on FOAF, get in touch sooner rather than later so little innaccuracies can be fixed early on (mailto:foaf-contact@rdfweb.org).
