Searching behaviour in a university library is studied using a wholistic approach, encompassing the use of bibliographic tools and shelf browsing. The present study is designed as the first half of a ‘before and after’ study to permit the evaluation of the impact of a future online catalogue on users' searching behaviour. A combined methodology was devised: searchers were encouraged to talk aloud during their search, and this information, together with some probing and real time expert interpretation, enabled the experimenter to record the searching activity on a highly structured observation form. The study reveals the extent of subject searching activity, and suggests that this may have been underestimated in previous studies. The analysis of expressed topics, search formulation strategy and documents retrieved reveals the adaptive nature of the subject searching process, whereby the user adapts to the structure of the available tools. The information retrieval task in a traditional library system 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 possible approaches in the searching process: the indexing language, the classification, and the titles. It is to be hoped that a future online searching environment will encourage a more truly interactive approach to subject searching.