Cross-Language Information Retrieval with a Multilingual Thesaurus and Cross-Concordances: The European Schools Treasury Browser (ETB) Michael Kluck Humboldt-Universität zu Berlin, Abt. Pädagogik und Informatik (HUB-PI) Informationszentrum Sozialwissenschaften, Bonn (IZ) 26th Annual Conference of the Gesellschaft für Klassifikation July 22-24, 2002, University of Mannheim, Germany Slides available at: http://www.educat-hu-berlin.de/~kluck/Etb-GfKl-2002.ppt

Overview the ETB project context the ETB thesaurus the cross-concordances in ETB the ETB search interface conclusion

European Schoolnet (EUN) and European Schools Treasury Browser (ETB) The European Schoolnet (EUN) is a cooperation and concertation activity of more than 20 European countries (Ministries of Education) aiming on the use of ICT in schools and providing tools and services which support information and cooperation mainly for teachers and pupils www.eun.org The European Schools Treasury Browser (ETB) is a project of the EUN and other partners to set up a network of networks of European educational servers to provide a seamless multilingual access to educational resources all over Europe etb.eun.org

Aims of the ETB project Network of European educational servers (national, regional): NNTP-network Not touching the autonomy of single servers Posting of all, selected or none resources (with European added value) Pulling of selected or none resources (related to the own editorial philosophy) integrated multilingual search at the ETB-Server individual proposal of resources via the ETB-Server

Examples of requests for the ETB server Schools searching for cooperation with schools in other countries dealing with similar topics Teachers searching for specific teaching materials: interactive resources on the free fall and gravity Pupils searching for projects of other classes on specific subjects: water pollution Teachers searching for language materials on specific topics

Handling of heterogeneity and multilinguality Developing a multilingual thesaurus Building cross-concordances between different thesauri and classification schemes like EET (European Educational Thesaurus) to ETB DBS-classification (Deutscher Bildungsserver) to ETB using the Thesaurus Management System (SIS-TMS) and mapping files (Excel) Setting up statistical transfer components between free text and thesauri or classification schemes for enhancing the search: (DBS) free text  ETB terms

What about the ETB Thesaurus? Real multilingual thesaurus in currently 9 languages: German, English, French, Italian, Spanish, Danish, Swedish, Greek, Hebrew Further languages will follow (depending on the offer of information sources and of language resources): Slavic languages, regional languages, official EU languages, less spoken languages Area of content (mainly): Online resources of schools, teachers, classes and pupils (learning materials, project results)

Building the ETB thesaurus Starting with empirical analysis: Existing educational thesauri (EET, EUN, ERIC, MOTBIS etc.) Usage of terminology in the Internet User queries of the DBS (log-files) Free keywords assigned to online resources by users of the DBS Building clusters / micro-thesauri Balancing within the micro-thesauri Balancing in between the languages

Advantages of a multilingual thesaurus

The properties of the ETB thesaurus Number of Descriptors ( = preferred terms): ~ 1160 (including countries + regions + languages) translated into all 9 languages Number of Non-Descriptors ( = not used, but indicating / leading to preferred terms), depends on activity of language groups and on available thesauri -> different number for different languages, not translated: German: ~ 280; English: ~ 260; French: ~ 860; Italian ~ 496 The high number of non-descriptors allows a better approximation of the users‘ vocabulary . Hierarchical structure with narrower (NT) and broader (BT) terms, additionally related terms (RT) and scope notes (SN), and association to micro-thesauri (MT), post-coordination.

Descriptors divided into micro-thesauri

Descriptors of the micro-thesaurus Content of Education (MT 70)

Non-Descriptors per language

German example descriptor in alphabetic display extracurriculare Aktivitäten MT (30) (70.70) Da: aktiviteter udenfor læseplan El: εξωσχολικές δραστηριότητες En: extracurricular activities Es: actividades extraescolares Fr: activités hors programme It: attività extracurricolari Sv: fria aktiviteter SN: Von der Schule initiierte und organisierte kulturelle, sozio-kulturelle und Freizeitaktivitäten, bei denen eine Teilnahme weder Pflicht ist, noch in die Bewertung der schulischen Leistungen eines Schülers einfließt. BT schulische Aktivitäten NT Aktivitäten in der freien Natur NT Auslandsaufenthalt NT soziokulturelle Aktivitäten NT Studienreise

Rotated display of descriptors Evaluation Evaluierung USE Evaluation Evolution (Biologie) Examen Experiment experimentelle Pädagogik experimentelle Wissenschaft  extracurriculare Aktivitäten Extremismus Fabel Fabrikationstechnik Fachsprache fachübergreifender Ansatz fachunabhängige Bildung USE intercurriculare Erziehung Fähigkeit zur Nutzung von Informationen Familie Beziehung Schule- Familie Ein-Eltern- Familie Gewalt in der Familie unvollständige Familie USE Ein-Eltern-Familie

German example descriptor in micro-thesaurus 30 SCHULISCHE AKTIVITÄTEN   schulische Aktivitäten top term . . NT1 extracurriculare Aktivitäten« (70.70) narrower terms on . . . . NT2 Aktivitäten in der freien Natur « (70.70) several levels . . . . NT2 Auslandsaufenthalt « (70.70) . . . . NT2 soziokulturelle Aktivitäten « (70.70) also belonging to 70.70 . . . . . . NT3 Ausstellung « (70.70) (polyhierarchy) . . . . . . NT3 Gruppenanimation « (70.70) . . . . NT2 Studienreise « (70.70) . . NT1 Hausaufgabe . . NT1 kreative Tätigkeiten . . . . NT2 Dramatisierung (Theater) term with explanation . . . . NT2 künstlerische Betätigung . . . . . . NT3 Modellieren . . . . . . RT Kunst (70.80) . . . . NT2 Modellbau . . . . RT Kreativität (10) related term

Snapshot of micro-thesaurus 70.70 EXTRACURRICULARE UND INTERDISZIPLINÄRE AKTIVITÄTEN extracurriculare Aktivitäten « (30) . . NT1 Aktivitäten in der freien Natur « (30) . . NT1 Auslandsaufenthalt « (30) . . NT1 soziokulturelle Aktivitäten « (30) . . . . NT2 Ausstellung « (30) . . . . NT2 Gruppenanimation « (30) . . NT1 Studienreise « (30) intercurriculare Erziehung . . NT1 Arbeitslehre . . . . RT Beruf (140) . . NT1 Bewusstseins sensibilisierende Aktivitäten . . . . RT Information (90) . . NT1 Erziehung zur nachhaltigen Entwicklung . . NT1 europäische Dimension . . . . RT europäisches Projekt (110) . . . . RT Europapolitik (140) . . NT1 Friedenserziehung . . . . RT Frieden (110) . . . . RT Solidarität (70.90) . . . . RT Toleranz (70.90)

What about cross-concordances? Setting up relations between existing thesauri and/or classification schemes by intellectual mapping of terms or codes Exact or inexact equivalence (=) Broader term (>) Narrower term (<) Loose relationship (^) One-to-one Logical expressions One-to-many Many-to-one Many-to-many No relationship

Cross-Concordances within ETB Cross-concordances between thesauri: EET terms --> ETB Thesaurus terms EUN terms --> ETB Thesaurus terms MOTBIS terms --> ETB Thesaurus terms Cross-concordances between classification schemes and thesaurus terms Deutscher Bildungsserver class. codes --> ETB Thesaurus terms INFOGUIDE classification codes --> ETB Thesaurus terms Lankskafferiet classification codes --> ETB Thesaurus terms Thesaurus Management System (SIS-TMS) (by FORTH)

Extract of a mapping table: EET thesaurus terms to ETB thesaurus terms EET term relator ETB term

Advantages of using the ETB Thesaurus and the cross-concordances Unique vocabulary which is used all over Europe Translations into other languages are already available Existing thesauri and classification schemes are re-used for mapping and statistical analysis Moderate further development (additions and/or changes of descriptors and mainly non-descriptors, enhancement of the cross-concordances and the statistical relations) Chance to offer all or selected documents via the ETB-network  there, it is possible to carry out multilingual searches