1. Høgskolen i Oslo Topic maps, a technology for knowledge organisation Presentation at ELAG 2004 Nils Pharo

2. Schedule l Topic maps is a standard for organising digital content l ISO certified in 2002 (ISO 13250) l Used for structuring web sites, knowledge management…

3. The basic elements of topic maps Topic maps consist of l Topics l Associations l Occurrences i.e. the TAO of topic maps (Pepper, 2002)

4. Ontologies l An ontology contains the topic map’s input l Examples of ontologies are thesauri, taxonomies, word-nets, etc l Ontologies are not necessarily structured hierarchically

6. Topic map technology l XTM – XML Topic Maps l HyTM – SGML based l Topic map engines using databases of various kinds l XTM + XSL

7. Example of XTM 1

8. Example of XTM 2

9. Example of XTM 3

10. Characteristics of topic maps 1. topics have names 2. topics are knit together using associations 3. a topic may be categorised by an unlimited number of topic types 4. topic types are topics on a higher level of abstraction 5. association types are association on a higher level of abstraction 6. occurrences may be external or internal to the topic map 7. topics can be disambiguated using subject indicators

11. Topic maps for knowledge organisation Two challenges: l Hierarchical versus associative structuring l Published Subject Indicators

12. Hierarchies and networks l Hierarchical in the thesaurus tradition with strict rules on what associative relationships should be allowed or l Open up for “unlimited” implementation of associative relationships

13. Published Subject Indicators l PSIs contain “definitions” of subjects l Who should provide such definitions? l Centralised control or principle of natural selection? l LIS traditionally aimed for control l WWW of anarchistic nature