Cross-concordances: terminology mapping and its effectiveness for information retrieval

The German Federal Ministry for Education and Research funded a major terminology mapping initiative at the GESIS Social Science Information Centre (GESIS-IZ), which found its conclusion in 2007. The task of this terminology mapping initiative was to organize, create and manage ‘cross-concordances’ between controlled vocabularies (thesauri, classification systems, subject heading lists) centred around the social sciences but quickly extending to other subject areas. Cross-concordances are intellectually (manually) created crosswalks that determine equivalence, hierarchy, and association relations between terms from two controlled vocabularies. Most vocabularies in our project have been related bilaterally. In a bilateral cross-concordance terms are mapped from vocabulary A to vocabulary B as well as relating terms from vocabulary B to vocabulary A. To date, 25 controlled vocabularies from 11 disciplines (see Figure 1) and 3 languages (German, English and Russian) have been connected with vocabulary sizes ranging from 1,000 – 17,000 terms per vocabulary. More than 513,000 relations were generated in 64 crosswalks.