AN EVALUATION OF AUTOMATIC QUERY EXPANSION IN AN ONLINE LIBRARY CATALOG

An automatic query expansion (AQE) facility in an online catalogue was evaluated in an operational library setting. The Okapi experimental system had other features including: ranked output 'best match' keyword searching, automatic stemming, spelling normalisation and cross referencing as well as relevance feedback. A combination of transaction log analysis, search replays, questionnaires and interviews was used for data collection. Findings show that contrary to previous results, AQE was beneficial in a substantial number of searches. User intentions, the effectiveness of the 'best match' search and user interaction were identified as the main factors affecting the take-up of the query expansion facility.