Contents

Status

The term foaf:focus does not exist yet.

It is likely to be added, and to serve the role of the previously proposed 'foaf:it' or 'foaf:isAbout' proposed properties.

See also SKOS Issue list

Example

SKOS concepts are a level of indirection from the things they're about; their creation dates and creators relate to their nature as information artifacts. So for example, we can have a SKOS concept standing for Bill Gates, and an RDF description of "Bill himself".

<skos:Concept>
 <skos:prefLabel>Bill Gates</skos:prefLabel>
 <foaf:focus>
   <foaf:Person>
    <foaf:name>Bill Gates</foaf:name>
   </foaf:focus>
 </foaf:apropos>
</skos:Concept>

Or in Turtle, switching from a personal to a geographic example:

<http://id.loc.gov/authorities/sj96005405#concept>
    a skos:Concept ;
    skos:prefLabel "Eiffel Tower (Paris, France)"@en ;
    skos:altLabel "Tour Eiffel (Paris, France)"@fr ;
    skos:inScheme <http://id.loc.gov/authorities#conceptScheme>, <http://id.loc.gov/authorities#topicalTerms> ;
    dct:created "1996-05-08T00:00:00-04:00"^^<http://www.w3.org/2001/XMLSchema#dateTime> .

... to which we might add:

<http://id.loc.gov/authorities/sj96005405#concept> foaf:focus <http://rdf.freebase.com/ns/en.eiffel_tower> .
<http://rdf.freebase.com/ns/en.eiffel_tower> a <http://rdf.freebase.com/ns/travel.tourist_attraction> .

This crosses us over from the bibliographic and cataloguing facts associated with LCSH's conceptualization of the Eiffel Tower, to worldly facts and claims about the tower itself. By naming this link ("foaf:focus") we can use such associations to find bibliographic artifacts via arbitrary properties of the thing they're about. For example, the nationality or birthplace of engineers, designers, managers etc.

Discussion

From #talis IRC

14:48 danbri: ldodds, re 'focus' as a property name (not it/apropos/isAbout) ... actually i like it for another reason:
14:49 danbri: sometimes there are a cluster of skos concepts which have a common focus but in thesaurus you get diferent aspects
14:49 danbri: shakespeare - youth
14:49 danbri: shakespeare - as englishman
14:49 danbri: shakespeare - rumours
14:49 danbri: i think the 'it' relation in each case most usefully points to the core thing of interest, ie. the person
14:50 danbri: ... ie the common focus of all those aspects which can be independently talked about in skos
14:50 danbri: whereas RDF class/property model is more thing-centric
15:27 ldodds: danbri: nice
15:27 ldodds: just emailing the list now
15:28 danbri: thanks!


Background

The idea of this property dates to SWAD-Europe-era SKOS discussions between DanBri and Alistair Miles (skos:it / skos:as). However the SKOS WG didn't standardise anything, and so we're including it in FOAF since FOAF has a few other topic-related properties already.

Naming discussion (danbri/ldodds)

12:21 danbri: is 'apropos'  too obscure as a property name?
12:21 ldodds: hey danbri -- I owe you a response :) ... I think its a little on the obscure side
12:22 ldodds: I see where you're coming from, but not sure its right. Its the other meaning of "apropros" that comes to mind first
12:23 ldodds: Also see your point re: isAbout
12:23 danbri: yeah, it's so tricky finding a nice word for rdf properties. Re 1st sense, maybe the concept 'fits' the thing?
12:23 ldodds: I was wondering whether we could borrow stuff from library/thesauri aspects of skos
12:23 ldodds: catalogues?
12:23 danbri: catalogues in what sense?
12:24 ldodds: As in "This Concept catalogues Gordon Brown"
12:24 ldodds: I'm not sure thats right either, but was thinking along lines of saying that a concept organizes material about something
12:24 danbri: timbl argued that foaf:knows would be better with a noun phrase, eg. foaf:contact
12:24 danbri: and i think avoiding verbs in the relation  does make some sense
12:24 ldodds: ok
12:24 danbri: but i don't know really
12:25 danbri: if you consider any single rdf vocab, you might get some stylistic consistency
12:25 danbri: but since they're all used together, it is necessarily pretty chaotic
12:25 ldodds nods
12:25 danbri: 'focus'
12:25 danbri: the concept 'focusses on' the thing?
12:25 ldodds: ooh, thats nicer
12:26 danbri: or 're'
12:26 danbri: for 'regarding'
12:26 ldodds: theme?
12:26 danbri: we had 'theme' in foaf before, for something libby made up
12:26 ldodds: ah
12:26 ldodds: I like focus though
12:26 danbri: http://xmlns.com/foaf/spec/#term_theme
12:26 danbri: 'The theme property is rarely used and under-specified. The intention was to use it to characterise interest / themes associated with projects and groups. Further work is needed to meet these goals. '
12:27 danbri: (and marked archaic)
12:27 ldodds: I missed that
12:27 ldodds: could be re-purposed I guess
12:27 danbri: foaf:focus is at least nice sounding, alliterative
12:27 ldodds: yes
12:28 danbri: focus might work better as a property of a project, the area it focusses on?
12:29 ldodds: maybe.
12:29 ldodds looks for synonyms
12:30 danbri is at dictionary.com :)
12:31 ldodds: theme suggests there may be several (un-related) themes for a concept, which isn't quite what we want to exporess
12:31 ldodds: focus is more explicit: this is what this category or concept is "about"