This paper defines performance measurement as the clarification of objectives and standards, identification of key activities, data collection and analysis, and formative evaluation of services. It then examines some of the factors involved in using performance measurement to evaluate public services activities, and analyzes performance measurement in three parts. The first part provides a general background on current evaluation theory. Building on this theory, the second part applies performance measurement to existing library activities through a model. The concluding section looks at the forces for and against public services performance measurements and future trends. The bibliography includes a selection of articles related to performance measurement; those relating to public services are grouped according to library functions (circulation, reference, etc.), and particularly useful methodologies or approaches are noted in the annotations. (THC)