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)

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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

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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

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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

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domain ontology

information fragments

reading/writing interface(generatedhyperdocument)

interfacespecficiation

hyperbook

Virtual Hyperbook Model

Domain ontology network of concepts, semantic links: "is a", "part of", "entails", …

Ontology-fragment links typed links between fragments and concepts

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Structure of a hyperbook

Tree

Graphis-a

exampleexample

example

Fragments

Concepts

Algorithm

property

Theorem. xxxxx yyyyy zzzz yy x dlkjs sls slssks sslsk

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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 Nselectcontentlinks

selection

assembly

N[q]......

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Node schema

Selection expression

over Fragments Ontology Links

Content structure

how to assemble the selected information

Links

navigation

or structural (inclusion, "expand-in-place")

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// 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

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Link inference

Tree

Graphis-a

example example exampleFragments

Ontology

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Link inference

Tree

Graphis-a

example example exampleFragments

Ontology

other example

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Link inference

Tree

Graphis-a

example example exampleFragments

Ontology

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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

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node show_fragment[F]

F.title

F.content

include related_fragments[F]

include related_concepts[F]

Complex node schema (inclusion)

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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

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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

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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

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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

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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 --> yby

x --> Concept c –SIM–> Concept c' --> y

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Cross book link inference

d csim

exampleHyperbook A

Hyperbook B

example example

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Node instance

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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

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Typed document similarity

Document similarity => concept similarity

A B

t t

document similarity(cosine, Kolmogorov,, ...)

semantic similarity

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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

HB1HB2...

node sch 2

SIM

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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