OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

xdi message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: Minutes: XDI TC Telecon Thursday 1-2:30PM PT 2011-03-31


Following are the minutes of the unofficial telecon of the XDI TC at:

Date:  Thursday, 31 March 2011 USA
Time:  1:00PM - 2:30PM Pacific Time (20:00-21:30 UTC)

ATTENDING

Giovanni Bartolomeo
Joseph Boyle
Kaliya Hamlin
Drummond Reed
Bill Barnhill


THE IDEARPAD LINK FOR TODAY IS:
     http://xdi.idearpad.org/27


1)  REVISED XDI GRAPH PATTERN DOCUMENT AND CORRESPONDING XDI STATEMENT DOCUMENTS

Drummond gave an overview of new version (2011-03-31) of the XDI Graph Patterns document together with a second document, XDI Statements for XDI Graph Patterns, that he uploaded before the call. NOTE: it appears OASIS has fixed the PDF bug - these links  were tested and worked fine.

  http://www.oasis-open.org/committees/download.php/41681/xdi-graph-patterns-2011-03-31.pdf
  http://www.oasis-open.org/committees/download.php/41683/xdi-statements-for-xdi-graph-patterns-2011-03-31.pdf


2) VERSIONING

Drummond briefly explained the updates to the versioning pattern, and the use of a relational arc labeled $v to the current version in the version metadata tree.

# GIOVANNI will send email about the versioning pattern.


3) PRIMARY/SECONDARY ADDRESSING PATTERN (SYNONYMS)

We discussed this topic in light of the new examples above and the messages on the list starting with this one from Giovanni:

  http://lists.oasis-open.org/archives/xdi/201103/msg00042.html

Drummond explained that, while he originally considered the XDI graph model to be a "multigraph", where the same parent and child nodes can be joined by more than one arc, in his work with the graph notation we have developed since Whistler last August, he believes that the rule needs to be one unique addressing arc per node.

Giovanni explained that he has been assuming a multigraph model in terms of addressability of context nodes.

Bill described a use case where you have =drummond and =bill, where =drummond is both a +friend and and +colleague of =bill.

   =drummond/+friend/=bill
   =drummond/+colleague/=bill

Drummond clarified that his point about not using a multigraph applies only to contextual arcs and literal arcs, not to relational arcs.

Drummond provided this example of the need to be able to make statements that apply to indivdual identifiers of context nodes. He suggested the classic case of an person who wants to be identified by both a persistent XRI (i-number) and a reassignable XRI (i-name).

Giovanni preferred to use an example of generic names for the same resource, such as +los.angeles and +city.of.angels. These are two XRIs that are intended to identify the same non-information resource.

Drummond said that if both XRI identify the same node in the XDI graph, he has not been able to figure out how to make an explicit graph statement of synonymity that does not involve a relational arc between two nodes, e.g.:

   =city.of.angels/$/=los.angeles

Giovanni explained that this is possible using a self referential arc labelled $. Actually this is the *only*  case in which a self referential arc has a consistent semantics, as it means that the node at which it is originated is the same as the node to which it ends. This (node identity) is an equivalence relationship thus it has three "qualities" [<--please replace with the correct English math word] (symmetric, reflexive and transitive) and is the graph counterpart of the statement =a/$/=b. Note that

=a/$/=a
=b/$/=b
=a/$/=b
=b/$/=a

can be read in the following graph:

    =a     _____ 
[] ------>[]  <__| $
|    =b   ^
-------------

Giovanni explained that this is a multigraph where both =a and =b are arcs from the first node (on the left) to the second node (in the middle). The $ is a reflexive arc on the second node.

Drummond pointed out that in this case, we don't even need the $ arc, because it would be assumed in the multigraph model that all nodes have the $ reflexive arc, and that all arcs that originate in the same parent node and target the same child node are synonyms using the $ predicate.

Drummond noted that we have consensus that we need to be able to express full equivalence relationships, i.e., the same relationship as owl:sameAs, and that the current Primary and Secondardy Addresses graph pattern example does NOT express this relationship.

Drummond wants to think about whether we need to continue to be able to express primary and secondary equivalence relationships.

# DRUMMOND to upload a new version of the XDI Graph Patterns and XDI Statements for XDI Graph Patterns documents with his revised thinking.

Bill adds that the four RDF/OWL world equivalents to what we are talking about are:
log:implies - unidirectional 'equivalence', use '-'?
owl:sameAs - bi-directional equivalence, use '='?
skos:broadens  -  subset relationship, use '$'?
inverse? - currently using $ in front of a predicate , repurpose !.

(see also  ongoing issue PROPOSED CONSTRUCTS/OPERATORS FOR XDI: http://wiki.oasis-open.org/xdi/XdiNewFoundation)


3) JSON SERIALIZATION

Drummond had an ephiphany about a simplified serialization format. See:

  http://lists.oasis-open.org/archives/xdi/201103/msg00036.html

He suggested that all TC members review this so we can update the JSON Format wiki page.


4) NEXT CALL

We agreed to skip next week's telecon because Drummond will not be able to attend next week due to attending the  Personal Data 2.0 Deep Dive Workshop at Telco 2.0 in Palo Alto.

The next call will be at the regular time in two weeks.

# DRUMMOND to arrange for GoToMeeting for the next call.


------------
ONGOING ISSUES LIST

Each of these is a candidate for the agenda for future calls.

* TRANSACTIONAL INTEGRITY FOR XDI (added 2011-03-24)

Since  versioning, as one example, involves multiple transactions that must be  commited as a group, we will need to address transactional integrity.  Specifically, we need to define how this will be handled at the protocol  level, vs. the implementation level.

* PROPOSED CONSTRUCTS/OPERATORS FOR XDI

Discuss the following wiki page originally posted by Giovanni:

  http://wiki.oasis-open.org/xdi/XdiNewFoundation

* DICTIONARY STRUCTURE

Mike would like an example of the PDX dictionary as soon as we can do it.

*   EQUIVALENCE SEMANTICS

Close on whether we need an additional $ word that is the equivalent
of Higgins Personal Data Model (PDM)  semantics   of h:correlation,
which is not as strong as $is.

      http://lists.oasis-open.org/archives/xdi/201006/msg00036.html

* COOL URIS

Continue previous discussion about the use of standard RDF URIs in XDI:

  http://lists.oasis-open.org/archives/xdi/201006/msg00023.html









[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]