A result of the Association of Research Libraries' (ARL) November 1975 Services Survey, this kit presents statistical studies developed from management information sources such as circulation records or generated expressly for a particular study. While academic and research libraries maintain statistical records measuring library efficiency or costs, concern has increased for determining library output or effectiveness, i.e., how well the library actually meets the users' needs. This concern relates to the library's ability to serve, with limited budgets, groups widely diversified in terms of information needs, academic level, and patterns of library use. The need to justify activities to the parent institution, to evaluate possible new services, to predict and influence change, as well as increased computer capabilities which facilitate the handling and manipulation of large quantities of data, and the establishment and funding of research offices in some libraries, have also encouraged the use and development of statistical data. Almost all libraries responding to the survey engage in some form of statistical data collection (whether it be continuous or formal research projects) reflecting the level and type of use of the libraries' service operations. This kit contains 17 documents from ARL libraries on continuing data collection and formal statistical studies. (THC)