1. and Coolheads Consulting A Processing Model for Topic Maps Knowledge Technologies 2001 Austin, 6 March 2001 Steven R. Newcomb (srn@coolheads.com) Michel Biezunski (mb@infoloom.com)

2. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Syntax is only half of the story Syntax is for interchange. Interchange Syntax is not enough for processing. Need an explicit processing model to describe what the result of processing is. XML technology is useful but not sufficient for topic map processing. Implementers must know the processing model in order to build interoperable applications.

3. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. What is a topic map? The answer you get depends on whom you ask. This situation is inconsistent with the use of topic maps for global knowledge interchange. Typical answers: –A kind of XML document, right? –A finding aid made from an XML document by a process of rendition…? –Whatever application X thinks a element means…?

4. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts The entire history was driven by idealists interested in solving the central problems of information management. 1993: First expression of Topic Map paradigm in Davenport SOFABED draft by Steven R. Newcomb. “Syntactically, topics are best represented as independent links!”

5. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 1993: Schism of Davenport Group project into –DocBook. (That’s another story.) –Conventions for the Application of HyTime (CApH), hosted by GCA Research Institute (now IDEAlliance), chaired by Steven R. Newcomb.

6. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 1993-1995: Several CApH drafts of topic map syntax and description, as a HyTime-conforming “Architecture Definition Document”.

7. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts Topic Map paradigm: Historical Facts 1995-1997: Michel Biezunski as pioneering hero of the Topic Map story –makes first implementations; –proves the value of the topic maps paradigm; –popularizes the paradigm; –serves the needs of real customers.

8. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 1997: Steve Newcomb and Michel Biezunski start working together again. With Martin Bryan, they become co-editors of ISO/IEC 13250. 1997: Peter Newcomb asks, “What’s the model?” Steve and Michel say, “What do you mean, ‘What’s the model?’?”

9. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 1997: Vicky Newcomb and Peter Newcomb eat tacos for breakfast at the Plano, Texas Whataburger. The model later known as “binding points” and “Whataburger” is born.

10. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 1998: Bryan Bell pays Steve and Michel to be locked in a room in Tacoma until they finish drafting ISO/IEC 13250.

11. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts Essential Dialectic Tension: –Biezunski’s Principle vs. –Newcombian incomprehensible elegance. Result: ISO/IEC 13250, with no explicit processing model, but total compatibility with Whataburger. Whataburger remains largely undisclosed, in the interests of getting the standard adopted.

12. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts 2000: ISO/IEC 13250:2000 finally, at last, adopted by ISO. It’s based on SGML and HyTime.

13. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map paradigm: Historical Facts GCA IDEAlliance (Dianne Kennedy, Paul Conn, etc.) prevails upon Michel and Steve to head up a new standards effort to make an XML Specification for Topic Maps as quickly as possible, in order to launch industries based on topic maps for the Web. Can we get the Whataburger model published and standardized at last?

14. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. What you need to know 1.A topic is a surrogate for a subject. 2.Subjects can be either indicated or constituted by resources. 3.Topics have characteristics: names, occurrences, and associations with other topics. 4.Topic characteristics are applicable within defined scopes. 5.Two rules govern the merging of topic maps: the subject-based and the name- based merging rules.

15. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. A Topic Map Processing Model Node types –t-node –a-node –s-node Arc types –association member –association scope –association template –scope component Topic-ification of resources

16. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. What is a topic map? Interchangeable topic map XML elements conforming to a structure defined by the XTM DTD. Interpreted topic map Application-internal graph resulting from processing the syntax. The topic map graph exhibits unambiguously all properties of topic map constructs. Formatted topic map Examples: HTML rendering of a topic map as an index; printed index.

17. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. What is a Topic? The computer representation of a subject (element or node) A set of topic characteristics: –topic names –topic occurrences –memberships of topics in associations

18. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Map Graph A set of nodes: t-nodes, a-nodes, and s-nodes.S T T A T T T T

19. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Subjects and Topics Subjects are notions. Topics are computer constructs. Topics are surrogates for subjects. subject topic

20. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topics have two aspects 1.Syntactical, interchangeable elements... 2.Application-internal nodes (t-nodes)T T A T T T TS

21. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. When two topics have the same subject... topic...Topics get merged into one t-node in the topic map graph. T T T subject

22. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Subjects and resources An information resource can indicate what the subject is, and/or an information resource can be the subject. subject

23. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Addressability of Subjects Subject is not addressable or Subject is addressable subject

24. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Subject Referencing Syntax subject

25. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. The Subject Identity Point Each subject can be considered a hub connecting all topics having this subject. Such a hub, called a "subject identity point", is a resource that either constitutes or indicates a subject. Therefore all s which refer to the same subject are to be considered the same topic.

26. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Two Forms of Associations Associations are computer constructs that take two forms: –Syntactic, interchangeable associations.... –Application-internal associations (a- nodes)T T A

27. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Associations and Topics Associations connect topics Associations can be considered as topics.T T A T A

28. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic Name Base Name: Name used to designate a topic. A topic may have zero, one, or several base names. A base name can be explicitly scoped. Each base name can have several variants, for various processes (display, audible rendition, sort,...)

29. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic-basename Associations The base name becomes a topic whose subject is the string resource that is the base name. A topic-basename association connects the named topic to its name, within some scope.

30. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Basename-variantname Associations The variant name becomes a topic whose subject is the information resource that is the variant name. A basename-variantname association connects the variant to the topic-basename association

31. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved.Scopes Topic characteristics have scopes. A scope is an extent of validity. A scope is represented as a set of topics.

32. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic namespaces Scopes are used to define namespaces for topics. TOPIC NAMING CONSTRAINT: No two topics can have the same name in the same scope (i.e., the same topic namespace). (This has absolutely nothing to do with "XML Namespaces".)

33. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. What gets scoped Scope applies to topic characteristics: –name, –occurrence, –role played in relation with other topics. Topics do not have scope. Only topic characteristics have scope.

34. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved.Occurrence Information resource attached to the topic because it is relevant to the subject that the topic represents.

35. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved. Topic-occurrence Associations The occurrence becomes a topic whose subject is the resource that is the occurrence. A topic-occurrence association connects the named topic to its occurrence, within some scope.

36. and Coolheads Consulting and © 2001, InfoLoom, Inc. and Coolheads Consulting. All rights reserved.More... http://www.topicmaps.net, a web site maintained by Michel Biezunski and Steven R. Newcomb.