The Thesaurus can be regarded as a result and a product of the documentation work which has been taking place at the LIS Library of the Library Institute since the early sixties. The processing and indexing of journal articles made it necessary to develop a system of subject categories, later a list of subject headings, on the basis of which a thesaurus was compiled in 1976, comprising 1015 descriptors and 1000 references. The changes in librarianship and library terminology require permanent revision of the descriptors. As a result the second revised edition was published in 1987.
The third edition of the Thesaurus was compiled first as a database (named THES) in 1991, with the thesaurus-management software attached to MicroIsis 2.3. As a computer print-out the Thesaurus was published in 1992. It comprises 1144 descriptors and cca. the same amount of references. Since then a printed version has not been published but the THES database (having now 1190 records, i.e. descriptors) is regularly updated.
In the second part of the paper the structure of the Thesaurus (the volume as a whole and the preferred term entries) is presented in detail, as well as the extension and development activities which are carried out permanently. A comparison is made with other LIS thesauri, i.e. with the LISA Online User Manual and the ASIS Thesaurus of Information Science and Librarianship, using various examples. The importance of the Thesaurus as a classification tool and as a retrieval language (assisting search in our MANCI database) is stressed. Our future plans include the publication of an English version of the Thesaurus the compilation works of which are underway.
Final abstract, August 25, 2000