Abstract:
This study describes end-user searching of a database of image descriptions in a television news setting, and evaluates the extent to which the database meets users' information needs. The PICS database (based on BRS/Search, a full-text information retrieval system) indexes and provides location information for electronic news graphics stored on videotape. Users search the database using a command-driven interface. Index terms are assigned from an inhouse thesaurus of subject terms. The system is not integrated in that the videotape must be mounted before an image can be viewed.
A detailed questionnaire, transaction logs and focus group interviews were the sources of data on user searching behaviour and opinions regarding PICS. The transaction logs revealed that the majority of searches were very simple, generally comprising one word, or two words joined by the AND operator. Searchers did not use features such as date limitation or restricting a search to a field, nor did they expand or restrict search results. Searchers used natural language almost exclusively. This contradicts users' self-reported searching behaviour where half the users reported using controlled vocabulary at least half the time.
Experienced users found the database easy to use, had few problems with the command interface, searched slightly more efficiently than inexperienced users, and reported slightly higher success rates. A majority of users stated they searched successfully at least 75 percent of the time. However, the transaction logs and responses to a question on their most recent search indicate that the actual search success rate is closer to 50 percent. Inexperienced users reported difficulty with use of commands, subject searching and expanding a search. The transaction logs revealed that searchers were using commands fairly proficiently despite these apprehensions.
Users generally found the training to be inadequate, especially the training given by an outside consultant, but were enthusiastic about receiving additional training. Users preferred one-on-one training by the librarian. Despite problems, users had a favourable overall attitude towards the database and found it easier to search and faster than the preceding manual system.
