Subject searching behaviour at the library catalogue and at the shelves: evaluating the impact of an online public access catalogue

Searching behaviour in a university library is studied using a holistic approach encompassing the use of bibliographic tools and browsing at the shelves. The project was designed as a `before and after' study to evaluate the impact of an online catalogue on subject searching behaviour. A combined methodology was devised using a talk-aloud technique, observation, and screen logging facility to elicit both verbal and non-verbal data from users in their searching activity at the manual bibliographic tools, including a microfiche catalogue and printed PRECIS index and at the online catalogue, as well as at the shelves. The data was recorded on a highly structured dual questionnaire and observation form with some real time expert interpretation. The limitations of the methodological approach of previous catalogue use studies are highlighted suggesting that subject searching as a basic primary need had been previously underestimated. The online catalogue does not seem to have increased the extent of subject searching nor the use of the bibliographic tool. An extensive qualitative analysis correlating expressed topics, search formulation strategies and documents retrieved at the shelves reveals the adaptive nature of the subject searching process, whereby the user adapts to the structure of the tools available. The PRECIS index supports a contextual approach for broad search formulations and more interactive reformulations whereas the OPAC encouraged a matching approach and narrow formulations with fewer but user generated reformulations. The success rate of the online catalogue was slightly better than that for the PRECIS index but fewer items were retrieved at the shelves. Nonusers of the bibliographic tools seemed to be just as successful. The information retrieval task in both searching environments is tailored by the system to a single one dimensional sequential process. It is suggested that a major obstacle to subject searching effectiveness may lie in the lack of interaction between the different subject access elements: the indexing language, the classification and the titles. The study concludes that to improve retrieval effectiveness online catalogues should cater for both matching and contextual approaches to searching. Recent research indicates that a more interactive process could be promoted by providing query expansion through a combination of searching aids for matching, for search formulation assistance-and for structured contextual retrieval