Today I attended a talk by Guus Schreiber, co-chair of the W3C’s Semantic Web Best Practices and Deployment Working Group, at Berliner XML-Tage 2004. Some choice quotes:
On good vs. bad ontologies: “Good ontologies are used in applications. They represent some form of consensus in a community.”
“Creating my own ontology is a misappropriation of the term. Ontology is about shared understanding.”
Showing a slide with lots of RDF/XML: “You see something like this in many presentations, usually with a much smaller font … RDF/XML is a good exchange format, but not good for communicating examples.”
He pointed to some alternatives: Dave Beckett’s N3/Turtle syntax and OWL abstract syntax. A UML Profile for OWL is in the works at the OMG.
Several new Semantic Web Best Practices Notes are being worked on. Upcoming subjects include: modeling Part-of relationships, numeric constraints, and qualified cardinality restrictions (A hand always has five fingers).
Other things being worked on: Best practices for vocabulary porting and management. RDF in XHTML (much discussion, no consensus. Mailing list). Converting existing ontologies and knowledge bases to OWL and RDF, beginning with WordNet.
Guus talked about some state-of-the art Semantic Web applications people have built. All apps focused on information integration and information presentation. Ontologies were used only to help with search (more general/specific terms). No reasoning, no agents.
Guus: “As a chair I have to do expectation management; that’s why I don’t like the agent scenarios.” Agents might be 8-10 years off, a standardization effort for rules 5 years.
On scalability of reasoning engines: “Description logics is useful for verifying small ontologies. For web applications, you mostly use subclass relationships and that’s it.”
“I’m very worried that the current W3C Semantic Web effort is too much text-oriented.”
Interesting talk showing that you can build useful SW applications today. The contrast between this talk, and the research efforts presented at the rest of the conference, is very revealing. Maybe this is a good thing. Semantic Web development is moving from academia into the trenches.
(More coverage of the conference in my German blog.)