Joint Committee Minutes 6 March 2001

Participants

• Mike Dean
• Frank van Harmelen
• Pat Hayes
• Jeff Heflin
• Jim Hendler
• Ian Horrocks
• Peter Patel-Schneider

Announcements

A public page containing various DAML briefings is now available here.

Last Week's Minutes

DAML+OIL (March 2001)

Initial discussion centered on Jeff Heflin's comments:

• UnambiguousProperty can only be used for abstract properties because it effectively involves an inverse property that only exists for instances. Unfortunately, this restriction limits the utility of UnambiguousProperty. ACTION (Ian): update the daml+oil.daml example for UnambiguousProperty to use instances.
• Peter and Ian included in the current documents a solution eliminating the requirement to tag individual data type values: intersect Literal with the set of possible types, then intersect with any subsequent constraints. These semantics are optimized for leaving the value as a string until you learn the actual type. ACTION (Peter, Ian): extend examples to show both tagged and untagged values. Peter believes that tagging should still be preferred.
• RESOLVED: DAML+OIL will include sameIndividualAs (a subproperty of equivalentTo) for relating instances of potentially different classes (e.g. Professor and Program Manager). It will also support differentIndividualFrom. ACTION (Ian, Peter): add these to the current specification.

There was consensus that we need more documentation for DAML+OIL, including more examples for concrete data types, explanations of restrictions, design rationale, serious drawbacks, etc. Jim Hendler and Dan Brickley (second hand) noted that we're leading the curve in some use of RDF. Even if (as expected), someone from the Joint Committee serves on the RDF Core WG and/or the expected Web Ontology WG, this provides extra motivation for documentating our decisions. Possible new documents include: introduction, FAQ, rationale, etc. separate from current reference. ACTION: Frank volunteered to draft a new introduction.

RESOLVED: In view of the additions and action items, we will wait until after next week's telecon to release DAML+OIL (March 2001).

Next Week

We'll plan to continue discussions from last week on what the Joint Committee should focus on next. ACTION (everyone): send new suggestions to Mike, who will collate for next week's agenda.

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