The idea of evaluation, or the measurement of a person, a service or a programme against some type of yardstick, has been around for a long time. In everyday language, the term evaluation is used to refer to everything from employee performance appraisal, to informal opinions about whether a particular service appears to be working well, to carefully planned and executed programmes of evaluation. In the past, librarians have tended to rely on their own professional judgement as a primary means of informal evaluation, and as long as the librarian was considered competent by others in the oganization, this method seemed to work reasonably well. In the rapidly changing fiscal climate of the 1990s, greater demands for accountability are altering the standards of evaluation, and informal methods based on professional judgement are less and less likely to be seen as adequate. Formal evaluation is becoming even more important as management strategies, such as total quality management (TQM) and continuous quality improvement (CQI), are adopted—strategies that rely on gathering and using data for measuring service quality. Although programme jargon such as TQM and CQI may change in the future, it is likely that the evaluation process inherent in these approaches will continue to be an important management tool for deciding on the allocation of scarce resources.