Agenda - XDI TC Call Wed. 7 December 9PM-10AM Pacific

XDI TC Members and Observers:

I apologize for the mix-up on last week's call; I called in before others and when no one else was there, went to another task. Take two tomorrow: we will discuss the same topic, this time with some additional detail from the draft i-tag spec (copied at the end of this message).

Following is the date/time, call-in info, and agenda for the next unofficial

XDI TC telecon.

Date: Wednesday, 7 December 2005 USA

Time: 09:00AM - 10:00AM Pacific Time

Dial-in number: 218-936-6666

Access Code: 2647893

AGENDA

1) DISCUSS XDI TRIPLE TRIPLE MODEL

This is a new proposal, inspired both by work on the "i-tag" initiative (see

http://www.seedwiki.com/wiki/itag/itag.cfm and in particular

http://www.seedwiki.com/wiki/itag/power_i-tags.cfm?wpid=220488) as well as

work on simple link contracts (as requested by Victor).

The proposal is that the XDI graph can be optimized not by just limiting it

to 3 levels deep, but also 3 levels "across". This means that everything in

the graph can be represented by an RDF "triple triple" -- a maximum of 3

linked RDF triples - a Subject triple, a Predicate triple, and an Object

triple.

We'll discuss as best we can in the absence of a shared whiteboard (which we

may want to arrange for future meetings).

Following is an HTML excerpt from the draft i-tag spec that explains this model in greater detail:

I-tag syntax is based on the RDF "subject-predicate-object" statement model.XRIs are used to serializing these RDF statements because:

XRIs support the use of global identifiers within other global identifiers (i.e., XRIs within XRIs, or URIs/IRIs within XRIs) in order to express structured, cross-context relationships.

XRI syntax enables the persistent identification of the resources (people, organizations, dictionaries, media objects) participating in an i-tagging relationship.

As applied to tagging, the RDF + XRI model maps as follows:

Statement part	Usage
Subject XRI	XRI identifing the authoritative source of the tag
Predicate XRI	XRI identifing the tag used to describe the media object
Object XRI	XRI that identifing the media object being tagged

This RDF model is then applied recursively one layer deep, so each of the three XRIs above can also be expressed using its own RDF triple. This yields the following matrix:

	Subject	Predicate	Object
Subject XRI	XRI identifying the author asserting the i-tag (e.g. i-name or URL)	XRI identifying the type of tag source (e.g., a blog, website, album)	XRI identifying the instance of the tag source (e.g. a blog name, web page name, album name)
Predicate XRI	XRI identifying the author defining the i-tag (e.g. i-name or URL)	XRI identifying the type of tag (e.g., tag, license, rating)	XRI identifying the instance of the tag type (e.g., tag name, license name, rating no.)
Object XRI	XRI identifying the author of the media object (e.g. i-name or URL)	XRI identifying the type of media object (e.g. blog post, video, song)	XRI identifying the instance of the media object (e.g. blog post number, video name, song name)

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