1. Hartwig Hochmair1 Institute for Geoinformation TU Vienna Revigis meeting Carnuntum 2001 Data Sources Used for the Navigation Process in the web

2. Hartwig Hochmair2 Outline Idea of my model for WWW navigation Two data sources for WWW navigation In which realms of WWW navigation plays semantic matching a role

3. Hartwig Hochmair3 Model: 2 data sources www use similarities of concepts for web navigation

4. Hartwig Hochmair4 Structure of web domain Vertical categories with subcategories Crosslinks (dashed) one single graph

5. Hartwig Hochmair5 User’s View: Aristotle’s Ontology object thingsbodiesqualitieseventsprocesses substanceaccident affordance [Gibson, 1977] attributesaction affordancesphysical object hierarchy

6. Hartwig Hochmair6 Structure of the Semantic Map

7. Hartwig Hochmair7 structure: list of graphs

8. Hartwig Hochmair8 Three Levels of Matching 1.web browser interface (interface level): advertised and afforded actions meaning of symbols meaning of technical terms 2.synonymy of perceived terms (context-level) 3.view of the world of web designer and web user (ontology level)

9. Hartwig Hochmair9 1. Interface Level B.Smith (1999): “In the world of information systems,…ontology is constituted by a specific vocabulary and programming environment” ontological engineers  philosopher-ontologists languages descriptions software representations representation in people’s mind objects properties states events processes

10. Hartwig Hochmair10 1. Technical Terms B.Smith (1999): “In the world of information systems,…ontology is constituted by a specific vocabulary and programming environment” ontological engineers  philosopher-ontologists independent of language software artifact for specific use computational environment

11. Hartwig Hochmair11 1. specific vocabulary for scientific domain Refresh Home Favorites Discuss Sychronize… Symbols:

12. Hartwig Hochmair12 1. specific vocabulary for scientific domain Refresh Home Favorites Discuss Sychronize… Symbols: Assumed as Common knowledge – not to be expclicitely modeled

13. Hartwig Hochmair13 2. Context Level One term has several meanings (polysemous terms) User-defined template: filled by information [Guarino 97] Template provides context

14. Hartwig Hochmair14 2. Example for Semantic Matching Red(X) this shirt is red (colour) a politician is a red (political direction) an Indian is a red (human race) in WWW navigation: clear through context

15. Hartwig Hochmair15 3. Ontology and Epistemology …the science of what is, of the kinds and structures of the objects, properties and relations in every area of reality [Smith 99] WWW: 2 different ‘ontologies’ –existing web structure (fact): ontology –user’s mental map (belief): epistemology

16. Hartwig Hochmair16 3. Overlap of Ontology and Epistemology All User Designer UDUD disjoint Area

17. Hartwig Hochmair17 3. Example for Successful Data Matching

18. Hartwig Hochmair18 3. Potential Problems (www) Error in web design: not designed for various user groups No absolutely ‘correct ontology’ => differences between web ontology (web designer) and web user. For example: caused by inconsistent subset relations in the web structure

19. Hartwig Hochmair19 missing inconsistency: clothing shoe where is link ‘shoe’ ?? user gets lost! clothingshoe

20. Hartwig Hochmair20 Conclusions Different levels of semantic matching applied in WWW navigation Problem: different ontology/epistemology 2 main data sources –different structure –represent same content

21. Hartwig Hochmair21 Kinds of Ontologies [Guarino 1997] top-level ontology domain ontologytask-ontology application ontology (sem. matching, Smith 1999) (symbols, similar voca- bulary, functions)