The effectiveness of a searching thesaurus in free-text searching in a full-text database

Searching thesauri which supply synonyms, antonyms and quasi-synonyms for given natural language terms have been suggested as a search aid to overcome these problems. To test these suggestions, a small searching thesaurus was constructed for Finnish newspaper articles on economic issues and a set of test searches were conducted and analyzed in a large Finnish newspaper article database. The original queries were elicited from journalists who also evaluated the relevance of the search results. Each query was searched in three distinct modes: basic search, synonym search and related term search. The searches in each mode were analyzed w.r.t. relative recall and precision by setting the relative recall of the third mode searches to 100%. The substitution of synonyms shows a considerable increase in recall with a negligible decline in precision