This report presents the objectives, methodology, and results of a study which assessed the selection and utilization of four MEDLINE search systems by faculty and medical residents at the George Washington University Medical Center. The four systems, which were provided or sponsored by the Himmelfarb Health Sciences Library, offer a wide range of information access and different levels of user interface: (1) miniMEDLINE, a locally mounted subset of the MEDLINE database which uses a very simple menu driven interface and is available from terminals at the library or via dial-access on the university's local area network or by modem; (2) SilverPlatter CD-ROM with MEDLINE database disks; (3) BRS/Colleague, a commercial search service with a "user friendly" interface that offers the entire MEDLINE file, additional related databases, and more than 15 journals and 25 textbooks in full text; and (4) Paperchase, a "poineer" user friendly computer program which allows physicians to simply and directly perform searches of MEDLINE. System preferences and characteristics are cross-tabulated with user characteristics to: (1) evaluate resident and faculty preferences; (2) determine if specialized search characteristics on the four systems affect system selection and differ by user group; (3) determine if search patterns differ by medial specialty group; and (4) determine the impact of library support on system utilization. Tables and graphs highlight the findings of the study. The survey instrument and 12 references are included. (MAB)