1. Towards Digital Libraries of Virtual Hyperbooks Gilles Falquet, Claire-Lise Mottaz Jiang, Jean-Claude Ziswiler CUI – University of Geneva ECDL'04, September 13-15, 2004, Bath (UK)

2. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 2 Outline Context  DL of hyperbooks (what we expect from...) Virtual hyperbook model  with ontologies  and interface spec. Reading/writing interface model  nodes schemas / interface definition  link inference Hyperbook integration  ontology integration or alignment  re-using the interface specification –several cases

3. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 3 Context Virtual documents and books  Set of informational fragments  Domain model (terminology, ontology, glossary)  Mechanisms to produce documents adapted to user's needs selection, assembly, presentation  Restriction: scientific or pedagogical (≠ fiction) monographs

4. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 4 Context Library of virtual books  Set of virtual books New access methods / reading possibities  Break the monolithic aspect of the book  Extend a book with contents of others  Generate new books  Compare, synthesize

5. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 5 Virtual Hyperbook Model Domain ontology  network of concepts, semantic links: "is a", "part of", "entails", … Ontology-fragment links  typed links between fragments and concepts

6. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 6 Structure of a hyperbook Tree Graph is-a example Fragments Concepts Algorithm property Theorem. xxxxx yyyyy zzzz yy x dlkjs sls slssks sslsk

7. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 7 N[r]... Reading/writing interface Interface = hypertext = nodes + links Interface specification  set of parameterized node schemas  Interface = set of node schema instances N[p]... node schema N select content links selection assembly N[q]...

8. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 8 Node schema Selection expression over Fragments  Ontology  Links Content structure how to assemble the selected information Links navigation or structural (inclusion, "expand-in-place")

9. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 9 // All the fragments linked to concept C node connected_fragments[C] {..... L.type, F.title, F.content.....} from Concept C –( L )– Fragment F A node schema selection content

10. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 10 Link inference Tree Graph is-a example Fragments Ontology

11. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 11 Link inference Tree Graph is-a example Fragments Ontology other example

12. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 12 Link inference Tree Graph is-a example Fragments Ontology

13. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 13 Node schema for link inference // Fragment related to F through a concept node related_fragments[F] {..... C.term, L2.type, href show_fragment[F2] (F2.title).....} from Fragment F –( L )– Concept C –( L2 )– Fragment F2

14. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 14 node show_fragment[F] F.title F.content include related_fragments[F] include related_concepts[F] Complex node schema (inclusion)

15. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 15

16. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 16

17. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 17 Hyperbook integration Library of virtual hyperbooks  a virtual book is not monolithic  the reading system should be able to compose new books from all the informational fragments of the library  semantic coherence must be garanted  a new virtual book inserted in the library should enrich itself by connecting to the fragments of the other books

18. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 18 Approach 1: Global integration A single ontology for all the hyperbooks Drawbacks  implies the unification of the book concepts (difficult, heavy task)  a single point of view  a single presentation style

19. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 19 Multi-point of view approach Each book represents a point of view  concepts may have different definitions Ontology alignment instead of integration  similarity links between concepts

20. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 20 Global reading in the integrated DL Extending a book Reading a book through the interface of another one  apply the interface (node schemas) of book A to book B Second level authoring  re-use existing node schemas or create new ones  new virtual book

21. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 21 Re-using an interface specification Re-use of a hyperbook interface and apply it to the whole library replace in the path link expressions x --> Concept c --> y by x --> Concept c –SIM–> Concept c' --> y

22. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 22 Cross book link inference

23. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 23 Node instance

24. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 24 Similarity links SIM links set manually or automatically for instance  [Rodrigez and Egenhofer] semantic similarity technique similarity of terms + similarity of attributes + similarity of semantic neighbourhoods + typed document similarity

25. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 25 Typed document similarity Document similarity => concept similarity A B tt document similarity (cosine, Kolmogorov,,...) semantic similarity

26. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 26 Implementation Hyperbook (frag. + onto + links)  relational database Interface spec  Lazy hypertext view system Similarity  computed and stored in DB  inserted by book manager node sch 1 HB1 HB2... node sch 2 SIM

27. ISIISI G. Falquet, C-L Mottaz Jiang, J-C Ziswiller 27 Ongoing and future work implementation and test of similarity algorithms experiments  collaborative writing of hyperbooks by students –"Formal methods for information systems" –"Information communication technologies" –"Information system interfaces"  hyperbook integration