topic maps and the ontological world

Topic Maps and the Ontological World

Dr. H. Holger RathDirector Research & Developmentempolis [email protected] – http://www.empolis.com

Roadmap

n Act I: Introduction

n Scene I: What are Topic Maps?

n Scene II: How do TMs work?

n Scene III: The Family of TM Standards

n Scene IV: TMs and Related Paradigms

Roadmap cont‘d

n Act II: Allegro

n Scene V: Ontologies, Schemas, Templates

n Scene VI: Class hierarchies

n Scene VII: Inferencing

n Scene VIII: Consistency constraints

n Scene IX: Topic Map Query Language (TMQL)

n Epilogue: Conclusions

Act I:

Introduction

Scene I:

What are Topic Maps?

An overview ...

The Sound-bites

n “GPS of the information universe”

n “A new paradigm for organizing, maintaining, and navigating information”

n “The bridge between Information Management and Knowledge Management”

Topic Maps are ...

n Standardized:

n An ISO standard describing knowledge structures, electronic indices, classification schemes, ...

n Web enabled:

n XML Topic Maps (XTM) are ready to use

n Designed to:

n manage the info glut

n build valuable information networks above any kind of resources / data objects

n enable the structuring of unstructured information

The 3rd Prophecy

Unified

Universal

Semantic

HTTP:// XML TopicMapsTopicMaps?! ?!

19911. Revolution

19972. Revolution

200320033. Revolution3. Revolution

By Tim Berners-Lee (father of the Internet)

Topic Maps – A Promising Technology

nMetadatan Topic Map data is not part of the info assets

n SearchnSearch in more precise topics and not in full text

n Linkingn TMs are well-organized link networks

n Knowledge structuresn TMs are a base technology for knowledge

representation

Scene II:

How do TMs Work?

Brief intro ...

Example: Back-of-the-Book Index

Don Giovanni .................. 56Leipzig .................... 35,90Lohengrin ..................... 49Mozart, W.A. .................. 11Mozart festival, see WürzburgWagner, R. .................... 22Vienna ..................... 11,42Würzburg ...................... 77


Topics



Occurrences



Differenttopic classes



Differentoccurrences classes




Multiple Topic Names

Don Giovanni .................. 56Leipzig .................... 35,90Lohengrin ..................... 49Mozart, W.A. .................. 11Mozart festival, see also WürzburgWagner, R. .................... 22Vienna ..................... 11,42Würzburg ...................... 77

Association


Book ContentTV Content Music content

MR. M. Random HouseBOL.com

Maria

C. SantanaThe Firm

Grisham DVDs

InterviewAuthorship

Publishing

Composership

Selling

Topic Map Concepts

Resources

Topics

Occurrencelinks

Associations

Assoc. classes

Subject Subject

Subject

SubjectSubject Subject

Subject

Subject


More Concepts

Occurrenceclasses

Topic classes

MR. M. Grisham

The Firm

Random HouseSanatana

Maria

BOL.com DVDs

Person

Thriller

Online shopPublisher

BandSong

Media

Article

Biography

Latest bestseller

Latest hit


More Concepts

Super classes

MR. M. Grisham

The Firm


Maria

BOL.com DVDs

Person

Thriller

Novel

Literature

AuthorJournalist

Association Concepts

Tina

Jim

Father John

Wife

Husband

Priest

Marriage

Role playingtopics

Associationinstance

Associationclass

Assoc. roles


More Concepts

Scopes

MR. M. Grisham Random HouseSanatana

Maria

BOL.com DVDs

The Firm (English)Die Firma (Deutsch)


More ConceptsIdentity

MR. M. Grisham

The Firm


Maria

BOL.com DVDs

http://www.topicmaps.org/PSI/authors.html#john-grisham

John Grisham

Summary: Topic Map Concepts

n Topic (reified subject)

n Occurrence

n Association, association role

n Topic class, occurrence class, and association class

n Class-instance

n Super-subclass

n Scope and scoping topic

n Identity and subject indicator

Scene III:

The Family of Topic Map Standards

ISO/IEC 13250, Data Model, Conceptual Model, TMQL, TMCL

Family of TM Standardsn ISO/IEC 13250:2000n ISO standard defining general concepts and interchange

syntax (SGML/HyTime + XML/Xlink)

n TM Data Modeln ISO project

n The foundation of the TM paradigm

n Independent of any particular (storage/interchange) syntax

n TM Conceptual Modeln ISO project

n Defines mapping between particular syntax (SGML and XML) and TM Data Model

Family of TM Standards cont‘d

n TMQL – TM Query Language

n ISO project

n ‘SQL’ for TMs

n Standardized creation/modification of TMs stored in TM Management Systems

n TMCL – TM Constraint Languagen ISO project

n Framework for the definition of ontologies / schemas for vertical or domain specific applications

n Support for semantic validation

Scene IV:

Topic Maps and Related Paradigms

Semantic Networks, RDF

Topic Maps and Semantic Networksn Pros of Semantic Networks:n Inheritance of node properties

n Inferencing

n Partitioning

n Formal notation

n Pros of TMs:n Occurrences

n Rich associations (n-ary, roles)

n Subject Identity

n Merging

n Standardized notation

Topic Maps and RDF

n TM / RDF – Similarities

nStructured, complex metadata

nBased on graphs

nStandardized notations

nKnowledge representation, ontologies

nHelp power the Semantic Web idea

n TMs on top of RDF ó RDF on top of TMs

Topic Maps and RDF cont‘d

n TM / RDF – Differences

‘toys’ (as of today)real products, projects, use

–merging

–distinguishes between addressable and non-addressable subjects

directed binary relationsn-ary associations with role players (instead of direction)

simple data structurepre-defined semantics

resource-centrictopic-centric

RDFTM

Act II:Allegro

TMs and knowledge representation

Quine‘s Criterion

What is there?

Quine‘s Criterion

Everything!

Scene V:

Ontologies, Schemas, Templates

The Starting Point …

TM Ontology

n John F. Sowa:

“Ontology defines the kinds of things that exist in the application domain.”

or

“A classification of the types and subtypes of concepts and relations necessary to describe everything in the application domain.”

“Real” TM

Infopool

is in is in takes place in

Austin

KnowledgeTech. 2001

U.S.A. Texas

Ontology TM

Topic classes Occurrence classes Association classes

country

state

city

conference

is in

takes place in

article

call f. papers

city map

video

Others:Assoc. roles,scoping topics

Ontology TM

Topic classes Occurrence classes Association classes

country

state

city

conference

is in

takes place in

article

call f. papers

city map

video

Others:Assoc. roles,scoping topics

These are all

These are all

Topics!

Topics!

Solution

n Terms TM Ontology, TM Constraint, TM Template, and TM Schema were coined by ISO committee

n Cover all TM constructs which have a declarative meaning:nAll classes and scoping topics

nClassification (see later)

nConstraints (see later)

=> ISO initiative TM Constraint Language (TMCL)

Scene VI:

Class Hierarchies

Building blocks are part of XTM

HUMAN

is instance of

Requirements

SPECIES

is instance of

MAMMAL

is subtype of

Graham Topic instance

is instance of

Requirements cont‘d

MAMMAL


Requirements cont‘d

SPECIES


is instance of

MAMMAL

is NOT aninstance of

Examples

n Topic classes:

Object →

piece of art →

painting, sculpture, novel, poem, opera

Person →

artist →

painter, sculptor, writer, poet, composer

Examples cont’d

n Association classes:

Object “fostered by” person →

piece of art “created by” artist →

opera “composed by” composer

Scene VII:

Inferencing

Deducing knowledge …

Association Properties

n Assoc: geo_object is in geo_object

n Properties: transitive, anti-reflexive, and anti-symmetric

n Facts in TM:Bavaria is in GermanyWürzburg is in BavariaMunich is in Bavaria

n Derived knowledge:Würzburg is in GermanyGermany is not in Bavaria

Inference Rules

n Class hierarchies and transitivity allow deduction of knowledge not explicitly coded in TM

n But TM might contains more knowledge which could be derived

n Inference rules define – as part of the ontology – how to derive further knowledge

Example

If $topic1 is sibling of $topic2 and $topic1 is male

then $topic1 is a brother

(Eric Freese, XML Europe 2000, Paris)

Rule components

n “if <condition> then <inference>” defines the inference rule

n “$topic1” and “$topic2” are variables which have to be instantiated when the rule is evaluated

n “is a sibling of” and “is a male” are the assoc. types in question

n “is a brother” is the inferred assoc. type

Scene VIII:

Consistency constraints

Dealing with millions of topics …

The Needs

nManual checking of large TMs is impossible but validation is a requirement

n TM software should validate during design and creationnPermanently or on demand

n Like structure validation in SGML/XML editors/parsers

n Constraints control validation process

=> ISO initiative TM Constraint Language (TMCL)

Examplen Topic type constraints:n Names (scope, number)

n Occurrence role (scope, number)

n Plays certain role in an association

n Example:n Person

n min. 1 englisch basename

n biography (exactly 1), portrait (max. 1)

n participates in born-in association

Example cont’d

n Association type constraints:n Scope

n Association role (number)

n Topic types of associated topics

n Example:n is in

n 1 Containee 1 Container

n city country, state, countycounty country, statestate country

Scene IX:

Topic Map Query Language (TMQL)

Query and modify TMs in a Standardized Manner

TMQL Sound Bites ...

n “Make Topic Maps Operational”

n “SQL for Topic Maps”

n “Backbone of Global Knowledge Interchange”

TMQL Applied to a 3-Tier Architecture

RDBMS TM MS

Business Logic

SQL TMQL

User Interface

TMQL

TMQL

XTM/13250

TMQL

TMQL

XTM/13250

TMQL System Context

XTM/13250

Application

Application

TMQL

TMQL

To

pic

Map

MS

Topic Mapdata model

Interchange syntax interface

TMQLinterface

Epilogue:

Conclusions

Topic Maps and the Ontological World

Conclusions

n TMs provide a simple but powerful paradigm

n Real products and real projects and real productive use 18 months after publication of ISO standard

n Accompanying standards (TMCL, TMQL) makeTMs ready for the Semantic Web and KM applications

n Harmonization with RDF

n But: TMs don’t aim at “Heavy Ontologies” (yet)

Some Resources

Addressable and Non-Addressable

Resourcesn Addressablen http://www.topicmaps.org

n [email protected]

n http://www.infoloom.com/mailman/listinfo/topicmapmail

n http://k42.empolis.co.uk

n Non-addressablen Standardization:

ISO JTC1 SC34 WG3n Vertical applications:

OASIS Member Section TopicMaps.Org and its various Technical Committees

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topic maps and the ontological world

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