This paper outlines a series of quantitative and qualitative models for understanding and evaluating the use of electronic scholarly journals, and summarizes data based on the experience of Project Muse at Johns Hopkins University and early feedback received from subscribing libraries. Project Muse is a collaborative initiative between the Press and the libraries at Johns Hopkins University to provide network-based access to scholarly journals including titles in the humanities, social sciences and mathematics. Project Muse has been produced from the outset for usability, with a focus on user-centered features. This has evolved as a participative and interactive process, soliciting input and feedback from users, and integrating user guidance components into the system. Six models of use analysis are discussed in this paper which cover both the macro or library-level and the micro or individual user-level activity: (1) subscribing organizations; (2) subscriber behaviors; (3) user demography; (4) user behaviors; (5) user satisfaction; and (6) user impact. Project Muse's success will ultimately be determined by its support for the electronic scholarly publishing objectives outlined in the Association of Research Libraries/Association of American Universities (ARL/AAU) work. (AEF)