EVALUATION OF INTERACTIVE QUERY EXPANSION IN AN ONLINE LIBRARY CATALOG WITH A GRAPHICAL USER-INTERFACE

An online library catalogue served as a testbed to evaluate an interactive query expansion facility based on relevance feedback for the Okapi probabilistic term weighting retrieval system. The facility was implemented in a graphical user interface (GUI) environment using a game-board metaphor for the search process, and allowed searchers to select candidate terms extracted from relevant retrieved items to reformulate queries. The take-up of the interactive query expansion option was found to be lower, and its retrieval performance less effective, compared to previous tests featuring automatic query expansion. Contributory factors including the number, presentation and source of terms are discussed.