A database of 212,278 records from the library catalogue was enhanced with subject descriptive fields from 7,186 records provided by Book Data Ltd, (a company providing bibliographic and marketing services to publishers).
Phase 1. of the project involved creating a database containing the enriched subject data and Phase 2. involved evaluating the resultant system.
The system was evaluated in a live setting using students and other library users as subjects. Both interviews and transaction logging were used to establish retrieval effectiveness and to examine users' responses to the adapted records. A controlled experiment was also carried out to measure the occurence of false drops.
Reactions to the system were favourable and users found it easy to navigate. Subject enhancement of records greatly increased recall, but at some cost to precision. Nearly all the enhanced records would not have been found without the enhancements. False drops were found to result largely from the false coordination of search terms in long text fields.