Re: [xdi] Minutes: XDI TC Telecon Thursday 1-2PM PT 2009-03-26

[Giovanni Bartolomeo <giovanni.bartolomeo@uniroma2.it>]

Hello,

sorry for not having able to attend this call. However, I'm starting 
to realize that we all have probably similar views, but not the same! 
This is probably due because we have started from an existing set of 
defined $ words, and we are assigning semantics to them trying to 
cover different use cases. A proposal could be to revert this 
procedure, starting from requirements and check what $ words we need 
(and what semantics should be them assigned). I've added this as an 
issue in the wiki page XdiMetamodel, focusing for the time being only 
on the usage of $ words in the metamodel: 
http://wiki.oasis-open.org/xdi/XdiMetamodel#head-97f5b1e080d47401763a7afd5e601ee766c5fea6. 
All comments are welcome!

Thanks,
Giovanni

At 06.31 27/03/2009, Drummond Reed wrote:
>Following are the minutes of the unofficial telecon of the XDI TC at:
>
>Date:  Thursday, 26 March 2009 USA
>Time:  1:00PM - 2:00PM Pacific Time (21:00-22:00 UTC)
>
>ATTENDING
>
>Markus Sabadello
>Nick Nicholas
>Drummond Reed
>John Bradley
>Bill Barnhill
>
>REGRETS
>
>Giovanni Bartolomeo
>
>
>1) CONTINUE $HAS AND +X/+Y/+X+Y DISCUSSIONS
>
>See the minutes of the last two meetings at:
>
>         [1] http://lists.oasis-open.org/archives/xdi/200903/msg00005.html
>         [2] http://lists.oasis-open.org/archives/xdi/200903/msg00018.html
>
>Also the posts at:
>
>         [2] http://lists.oasis-open.org/archives/xdi/200903/msg00004.html
>         [3] http://lists.oasis-open.org/archives/xdi/200903/msg00006.html
>         [4] http://lists.oasis-open.org/archives/xdi/200903/msg00007.html
>         [5] http://lists.oasis-open.org/archives/xdi/200903/msg00008.html
>
>The main page we discussed on this call was the new XDI Metamodel page:
>
>         http://wiki.oasis-open.org/xdi/XdiMetamodel
>
>We began by discussing the proposition brought up last week, i.e., that the
>$has predicate emight be a generalization of all predicates (all arcs). Bill
>explored this by explaining all the pairings he derives from
>=abraham/+son/=isaac (@=, =abraham), (+metadata+described, =abraham),
>(=abraham, =abraham+son), (+son, =abraham+son). He said they are in the form
>(group-id, member-id).
>
>Drummond explained that he felt strongly that $has was not the
>generalization of all predicates, but in fact that it had very specialized
>purpose and semantics vs. $has$a. For example, =abraham+son infers the
>metagraph statement =abraham/$has/+son. This also asserts a cardinality of
>exactly one +son outgoing arc from =abraham that has an object =abraham+son.
>
>In addition it infers that:
>
>         a) =abraham/$has$a/+son, but does NOT infer any cardinality of the
>number of sons.
>         b) =abraham+son/$is$a/+son, but does NOT infer any instances of
>sons.
>
>We then compared RDF and XDI RDF statements. Bill gave the example:
>
>         foaf:Person has a property ex:son
>         Abraham is a instance of foaf:Person
>         Abraham has a property of ex:son
>
>Those same statements in XDI RDF (roughly):
>
>         +person/$has$a/+son
>         =abraham/$is$a/+person
>         =abraham/$has$a/+son
>
>Drummond pointed out that the last statement means =abraham/+son, not
>=abraham+son. The latter would be the metagraph statement
>=abraham/$has/+son.
>
>Bill said that in term of his groupID, memberID pairs, this would be
>+person=abraham, =abraham+son.
>
>Drummond gave the same example in English of "Boeing has a airplane called
>[list of airplane objects here]" and "Boeing airplanes" as a noun.
>
>
>Bill said, "So you're saying @boeing+plane(xx) => (xx) is a class, and
>@boeing/+plane/(xx) => (xx) is an instance? Drummond agreed.
>
>Nick noted that there is a confusion between $has at the graph and metagraph
>level, and also that we need to discuss arcs between two individuals (vs.
>arcs from a class to an individual).
>
># DRUMMOND to make that a topic for next weeks call.
>
>Bill also noted the following link to a good series of posts on A-Box vs
>T-Box:
>
>         http://www.mkbergman.com/?p=471
>
>And also that for the next call, one method of whiteboarding is to use the
>Coccinella client:
>
>         http://thecoccinella.org/download
>
>
>2) NEXT CALL
>
>Regular time, 1-2PM PT (20:00-21:00 UTC).
>
>
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