Part IV is a summary analysis of sample and survey data collected to facilitate the structure of the cost assessment models and to find out which, if any, subgroups of HAM-TMC user population make more (or less) use of various library services. Sampling data were obtained from brief interviews and in-house files of various user institutions to discover how medical and nursing professionals and students used six library services: in-house-use, reference services, interlibrary loan, manual bibliography searches, computer searches, and photocopying on-demand. Results are displayed in tabular form for user groups studied. In most cases, meaningful differences were not found in the intensity of use by user category; however, differences were found in relative amount of usage of these services. To help provide additional data, a three page questionnaire was distributed to 542 persons at 14 of the institutions served by the HAM-TMC library. Included in the survey were M.D.'s, Ph.D.'s, D.D.S.'s, M.S.'s, interns, and residents; excluded were medical and nursing students. Data from the 303 completed questionnaires which were returned were analyzed to determine differences that might exist among subdivisions of the user survey sample. Either the t-test or chi-square test was used, depending upon the situation, to test for statistical significance at the 5 percent level. Results are presented in both tabular and descriptive form, and a copy of the questionnaire with tabulated responses is appended. (Author/JPF)