# Presentation: 139911

## XTM Update			

- Michel Biezunski (mb@coolheads.com)
**XML Working Group, xml.gov**
- March 20, 2002, Washington, DC

- Coolheads Consulting

## Outline

- Overview of Topic Maps:
- Requirements
- The paradigm
- What's to come:
- RDF/Topic Maps Unification
- The work in progress at ISO
- XML and Topic Maps

## Requirements for topic maps

- Address the Infoglut problem:
- improved findability of information
- Reliability:
- improved trust, establishing identity of information item.
- Provide reliable addressing
- Efficiency:
- Track and eliminate redundancy. Knowledge integration.
- Distributed authority:
- Local ontologies and distributed knowledge sharing
- No single central repository will do.

## A standard

- ISO/IEC 13250:2000 Topic Maps
- XML Topic Maps added in 2001 to the ISO standard.
- Editors: Michel Biezunski, Martin Bryan, Steven R. Newcomb
- Made available for free by the DOE: http://www.y12.doe.gov/sgml/sc34/document/0129.pdf
- Built over 8 years.
- 20/80 rule: 20% technical, 80% political
- Is now becoming an industrial reality
- Implementations: Publishing industry project, Government Agency, Pharmaceutical industry, Legal
- Several products already available: commercial, public domains, prototypes, etc.
- Gives rise to a new electronic publishing paradigm.
- Is becoming part of the Semantic Web initiative.
- Is being extended for optimizing large-scale interoperability.

## Topic Maps Timeline

| 2002 | OASIS published subjects
Topic Maps expressed in RDF?
Work in progress on Reference Model/Standard Application Model |
| --- | --- |
| 2001 | XTM 1.0  revised (February). XTM 1.0 DTD incorporated into ISO/IEC 13250 |
| 2000 | December: XTM 1.0 (Core), XML Topic Maps
January: ISO/IEC 13250 (Topic Maps) released. NewsML |
| 1999 | RDF: Resource Description Framework |
| 1998 | XML |
| 1996-2000 | ISO/IEC 13250 (Topic Maps) |
| 1993-1995 | CApH: Conventions for the Application of HyTime |
| 1991-1995 | Davenport (SOFABED): Interoperable indexes |
| 1988-1992 | HyTime: Addressing, Linking and Scheduling |
| 1986-1988 | SMDL: Standard Music Description Language |
| 1986 | SGML: ISO 8879 |

## The Topic Maps Paradigm 

- The Topic Maps Paradigm

**User-**
**defined**
**semantics**

## Basic Topic Map Constructs

- Association

- Topic

- Occurrences

- Scope
- (name spaces)

- Several names

## Subject Identities

- Each topic is the computer representation of a subject, and only one subject.
- The author of a subject has the authority to define what it means, and what its intended uses are. This authoritative definition need not be unique. Competition for trust, reliability for establishing subjects.
- Subjects can be either themselves objects of information (a Web page can be a subject) or they can contain information indicating what the subject means.

## Something new for the Semantic Web

- An information resource can **indicate** what the subject is,
- and/or
- an information resource can **be** the subject.

## Current development in Topic Maps

- Sanity check: Are we all on the same page?
- API-level interoperability, syntax independence
- Predictable results from merging operations
- Support for predictable scaling metrics
- Basis for 	Constraint and Query Language
- Predictable addressability
- Basis for bridges to other standards, e.g. RDF

## Overlap with W3C's RDF?

- Some overlap
- Both standards usable to provide semantic connections for data/metadata
- RDF model is simpler, more "processing-oriented" than "data-oriented" (Subject --- Predicate --:> Object)
- Topic maps provide higher level constructs to describe knowledge objects.
- Both are necessary:
- Like the "atom" seen in Physics and in Chemistry.
- They can be made work together:
- TM can be "exploded" into primitives represented as RDF statements.
- RDF schema of Topic Maps to come...

## Work in progress at ISO

- The Standard Application Model Approach
- Maximum relevance to current industry needs
- Defined information set covers but is not limited to the information set commonly supported by existing APIs
- Formalisms consistent with mainstream XML industry practices: Infoset, UML
- The Reference Model Approach
- Maximize the generality of the paradigm
- Support for multiple application models
- Make sure that knowledge will fuse even when the sources don’t cooperate
- See everything in terms of a single, abstract analysis of the nature of assertions
- Preserve the value of addressing expressions

## XML and Topic Maps

- Topics maps are expressed and interchanged in XML
- Topic Maps provide "out-of-line tagging":
- Multiple perspectives on the same information
- Use, and assembly, for different purposes that the ones that were originally intended.
- Topic Maps simplify use of XML.
- No need to express information within a single DTD/Schema
- Interoperability between various XML Schemas/DTDs

## Discussion

- Michel Biezunski
- Coolheads Consulting
-  mb@coolheads.com
- http://www.coolheads.com