This volume is the most comprehensive compilation of ideas related to library performance yet assembled. It brings together noted researchers and successful library directors and educators who have extended the landmark findings and efforts of their mentor and friend, Ernest DeProsp. The editors give a historical account of contemporary measurement activities; suggest methodologies for measuring performance; offer viewpoints on planning, goal-setting and validity; and comment on problems associated with planning, one of the major tools of measurement. Readers of the book will develop informed opinions about planning, a practice that when entered into unaware can enslave an organization in endless data gathering routines and tax their endurance beyond reasonable points. Thought-provoking comments on the directions taken, and not taken, by library thinkers challenge the reader to speculate about current library-think.