Hi Bob, I like the basic idea here because it matches a real modelling need to represent ordered collections/lists. A vocabulary for that can be submitted as a design patterns on ODP [1] for public utility.
However, why do you want to represent ordered lists, slots and items as [ rdf:type owl:Class ] (or rdfs:Class)? While a list is a set mathematically speaking, is there any advantage in representing the lists you want to talk about as sets? This has some bad consequences. In your example, SexMachine and GoodFoot are inferred to be [ rdf:type owl:Class ], not only [ rdf:type mo:Track ]. Therefore James Brown results to be the author (foaf:made) of an owl:Class (SexMachine), ehich is at least awkward :). In order to avoid this consequence, while preserving the basic intuition of your vocabulary, you can have ordered lists, slots and items as [ rdf:type owl:Thing ] instead. As a related example that follows this practice, on ODP, there is the "collection entity" pattern [2], which can represent any kind of collection/list, and can be extended with your vocabulary to represent ordered lists with slots and indexes. Best Aldo [1] http://www.ontologydesignpatterns.org [2] http://www.ontologydesignpatterns.org/cp/owl/collectionentity.owl On 28 Jun 2010, at 09:58, Bob Ferris wrote: > Hello everybody, > > in a longer discussion in the Music Ontology mailing list about how to model > a playlist, Samer Abdallah came up with a very good proposal[1] of modelling > a sequence/ordered list (as recently also discussed at RDFNext Workshop[2]) > as semantic graph (in RDF). > So, here we go: > > - specification[3] (please also note the anonymous inverse properties) > - concepts and relations in a graphic[4] > - funky playlist example[5,6] > > Again, thanks a lot Samer Abdallah for that cool concept. > Comments, suggestions, critics are very welcome. > > Cheers, > > > Bob > > PS: its all OWL based ;) however, we could also downgrade the concept on the > basis of rdfs:class, if needed. > > > > [1] > http://groups.google.com/group/music-ontology-specification-group/msg/305a42362a1e4145 > [2] http://www.w3.org/2009/12/rdf-ws/slides/rdflist.pdf > [3] > http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/rdf/orderedlistontology.n3 > [4] > http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/gfx/olo_-_orderedlist.gif > [5] > http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/examples/orderedlist_-_example.n3 > [6] > http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/gfx/olo_-_orderedlist_example.gif > > _____________________________________ Aldo Gangemi Senior Researcher Semantic Technology Lab (STLab) Institute for Cognitive Science and Technology, National Research Council (ISTC-CNR) Via Nomentana 56, 00161, Roma, Italy Tel: +390644161535 Fax: +390644161513 aldo.gang...@cnr.it http://www.stlab.istc.cnr.it http://www.istc.cnr.it/createhtml.php?nbr=71 skype aldogangemi
