Re: XFML & RDF

My Knowledge Explorer automatically checks for
mutually exclusive classes, and could enforce it
if desired.
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart list of proposition

  ----- Original Message ----- 
  From: Danny Ayers 
  To: RDF-Interest ; xfml@yahoogroups.com 
  Sent: Sunday, November 03, 2002 3:18 AM
  Subject: XFML & RDF



  A list crossover post, I think the intersection raises interesting questions
  on both sides.

  XFML (eXchangable Faceted Metadata Language) is a lightweight language for
  classification, which draws largely from the Topic Map tradition. The
  representation of this information in RDF could I think be very useful (the
  language is already in use for syndication feeds - see the purple icon at
  the bottom of [6]). Below is a description of the key term in this language,
  and my initial thoughts looking at it from an RDF point of view.

  There is a public space for discussion of this that doesn't involve getting
  tangled up with the mailing lists - the XFML Wiki [4].

  Cheers,
  Danny.

  ----
  from [2]:
  Facets are mutually exclusive containers that contain hierarchies of topics.

  Mutually exclusive means that a certain topic can only possibly belong to
  one facet. "Things to do" and "Places to go" are good facets, because a
  topic can never be both a thing to do and a place to go to. "People" and
  "Colours" are two other good facets. "Cities" and "Places to visit" are bad
  facets if used in the same map because "Brussels" (a potential topic) could
  belong to both. Note that the "mutually exclusive" requirement is not
  something that can be enforced by software.
  ----

  My first impression is that the facets can't be expressed in vanilla RDF
  because of the mutual exclusion requirement. However, the DAML+OIL language
  [3] (and its forthcoming successor, OWL [7] (not Lite)) contains
  daml:disjointWith, so I think facet could probably be expressed as a class
  through this. Apart from the 'facet' term itself, I think everything else
  can be expressed fairly easily in RDF(S), mostly following existing XTM/RDF
  mappings [5].

  There may still be problems in regards to the open/closed world assumptions
  and the extent of the exclusivity (I'm not quite clear enough in my
  understanding of XFML or logic!).

  [1] http://xfml.org/
  [2] http://www.xfml.org/spec/1.0.html
  [3] http://www.w3.org/TR/daml+oil-reference
  [4] http://xfml.net/index.php?page=XfmlAndRDF
  [5] http://www.w3.org/2002/06/09-RDF-topic-maps/
  [6] http://www.iaslash.org/module.php?mod=syndication
  [7] http://www.w3.org/2001/sw/WebOnt/


  -----------
  Danny Ayers

  Idea maps for the Semantic Web
  http://ideagraph.net

  <stuff> http://www.isacat.net </stuff>

  Semantic Web Log :
  http://www.citnames.com/blog