With the aid of a grant from the Council on Library Resources, The New York Public Library's Research Libraries conducted an experiment lasting from July 1971 through March 1972. The object of the experiment, which was in three parts or phases, was to determine the acceptability of microfilm as a substitute for the public card catalog, the new book catalog, and the authority file for the new book catalog. Because many of the cards in the heavily-used public catalog are badly deteriorated and in need of replacement, various alternatives, including microfilming and book publication, have been studied. Part I of the experiment was designed to test the feasibility of the first of these alternatives. Parts II and III, involving the use of microfilm as a substitute for the authority file and the new book catalog, as it related to the Processing Division, are reported on by the Chief of that Division. Part III also involved public use of The Research Libraries new book catalog on microfilm. A report on this part forms the final portion of the report. (Author)