A statistician in the Intelligence Unit of the Greater London Council.

The views expressed are the personal views of the authors and not necessarily those of their Departments. Output measures for libraries need to be improved. One possibility would be to incorporate in catalogue entries and charging codes a symbol indicating the nature, and hence the main potential use, of each adult non-fiction title. This article describes experiments conducted by the Public Library Research Group with the objective of defining such categories. Effective management demands some means of measuring the extent to which the organization is achieving its objectives, and public libraries have found it particularly difficult to devise output measures for this purpose. A crude count of the number of books issued or on loan is of very limited value, even when analysed into fiction, non-fiction and children’s books, or-in the case of non-fiction-into subject categories. The quality of the service given and the nature of the library’s contribution to the community-for example, the extent to which it is assisting advanced studies, meeting the more general needs of serious readers, or providing a mainly recreational service-cannot be assessed by such means