The objectives of this study undertaken for the National Library of Medicine were to develop a list of issues and criteria that relate to the problem of measurement of medical library effectiveness. The procedure employed was to review the literature on the subject of library evaluation. Each criterion or measure of evaluation encountered was placed on a list of criteria and examined in terms of its potential significance and validity for measuring library performance. The first section of this report contains a discussion of some of the factors involved in measuring library performance and an outline of existing evaluation methods. The second section is devoted to discussing individual studies and the evaluation criteria that were used. In the third section areas in which it is believed additional research will produce sound method(s) of evaluating total library performance are discussed. The final section is devoted to the analysis data from the University City Science Center's "Final Report - National Survey of Medical School Libraries." (Author/NH)