A continuation of the conversations that started in Montreal at the Extreme Markup Languages Conference to increase knowledge and understanding about the relationships between the W3C RDF and ISO/XML Topicmap activities.
[[[ Relationship of XTM and RDF The actual and potential relationship of XTM and RDF was discussed, since there had been public comment about this issue during the Extreme Markup Languages Conference immediately preceding the XTM meeting in the same hotel. Specifically, conference co-chair Michael Sperberg-McQueen had suggested in his closing keynote that the RDF people and the Topic Maps people should be locked in a room together until they have harmonized the two standards. A "summit" meeting on this issue has been proposed by Eric Miller, who would host such a meeting at OCLC. The AG, with the help of its three Subgroups, needs to: - Understand the relationship, if any, between the XTM conceptual model and RDF conceptual model, - Understand what realistic opportunities exist for establishing one or more syntaxes that will be common to both Topic Maps and RDF, if any, and - Understand the Use Cases, if any, that compel harmonization or unification of Topic Maps and RDF around either their conceptual models or their syntactic models, or both. ]]] -- XTM Agenda http://www.egroups.com/files/xtm-wg/Meeting+Agendas+%26+Summaries/minutes0823.htm Thu, 01 Jan 1970 00:00:00 GMT
Steve, Michel, could you reiterate again the differences between ISO Topicmaps and the XML Topicmap activities.
[[[ Facing the conflict between Topic Maps and RDF head-on, the conference staged a debate between Eric "RDF" Miller of OCLC and Eric "Topic Maps" Freese of ISOGEN. Freese and Miller provided this comparison between the two specs: Similarities between RDF and Topic Maps Both specifications are hard to read share a goal: to tie semantics to document structures provide a systematic way to declare a vocabulary and basic integrity constraints provide a typing system provide entity relationships both work well with established ontologies The correspondences between the specs look something like this: RDF Topic Maps Resource Topics RDF schema TM templates (proposed) Properties Facets and association roles URIs Topic identity, scope Reification Association IDs Differences between the two specifications Topic Maps are not XML-specific and have so far been standardized for SGML only. The XML Topic Map activity under the GCA's IDEAlliance is drafting a proposal for such an implementation. RDF is also not XML-specific, but to date has been implemented only in XML RDF now has which provides a standard way to express and link an ontology; such a schema is proposed for Topic Maps RDF uses XML linking, Topic Maps use HyTime linking Topic Maps have explicit scoping Topic Maps start with the abstract layer and (optionally) link to resources; RDF starts at the resource layer and (optionally) creates an abstract layer Modeling Topic Maps with RDF "loses the distinction between topics and resources," according to Freese. In preparation for Montreal, he put out a call for suggestions on how to combine the two to end up with the best that each has to offer. Here are some of the suggestions: consider topics as collections of resources (anchors) or links such that one object can be a link by a link interpreter and a topic by a Topic Map interpreter add RDF's frame-based notation to Topic Maps to attach properties to resources model RDF as a Topic Map application, gaining the scoping, merging, and inheritance mechanisms David Dodds provided one view of an RDF/Topic Map alliance in his paper, "Simultaneous Topic Maps and RDF Metadata Structures in SVG."  In this application, he embedded Topic Map constructs in RDF metadata within SVG resources. With this notation, a graphics application would then know that a bar chart is a bar chart, and that each bar represents a certain scale and quantity. Since the RDF is embedded in a map, an external Topic Map processor can also manipulate the image. Freese's example of the best of both worlds would look like this: <topic xlink:type="extended"...etc...> <resource xlink:type="locator" xlink:href="...etc..." rdf:type="dublinCore"> <dc:author>Dr Livingstone</author> <dc:language>english</language> ...etc... </resource> </topic> This example attaches a set of properties to a locator, which is a link. The topic could also be an RDF frame and, therefore, could contain any kind of property. The reaction of the user community in Montreal was strong and unequivocal: merge the two or at least make them compatible. Among the desirable outcomes that were mentioned was a new syntax for RDF that would retain the graph notation but be less difficult to use. ]]] -- XML.com - Part 2 - Going to Extremes http://www.xml.com/pub/2000/09/13/extremes2.html Thu, 01 Jan 1970 00:00:00 GMT
Useful simply to start listing examples:
Should we consider establishing a public archived mailing list for RDF <-> TopicMap discussions, or are we all happier working in private cc:'s initially? If public, whats the name, where?
Where, when, does this forum (teleconference && IRC) work?