Although there is a proliferation of information available on the Web, and law professors, students, and other users have a variety of channels to locate information and complete their research activities, the law library catalog still remains an important source for offering users access to information that has been evaluated and cataloged by experts. The usability of the catalog needs to be effectively measured before any necessary improvements can be made. This study was undertaken to investigate the information retrieval patterns of users of the Rutgers Law Library Online Public Access Catalog and to develop the catalog into a more effective search tool for these users. This study used an experimental approach to measure the usability of our catalog by analyzing the transaction logs from the OPAC system and the results from Google Analytics. The findings provided not only important information on user demographics and their computer systems, but also more insight on the search behaviors of users. The specific findings included the following: (1) As a Web-analytic tool Google Analytics provided extensive information on the OPAC and the navigational behaviors of users; (2) Fifty-eight percent of our users visited the Web site regularly; (3) The most popular search method, which was employed by 37% of our users, was by title; (4) Most patrons used computer systems with a high resolution and color depth monitor and visited the catalog Web site with a high-speed Internet connection; and (5) Suggestions were made by the authors to improve the users' search experience of the catalog Web site. This study is significant to libraries with Web catalogs because it demonstrates the potential value of using Google Analytics as a Web analytics tool in combination with the OPAC transaction logs to measure catalog usability. (Contains 6 figures and 26 notes.)