A B S T R A C TThis study used two successive phases of usability testing to evaluate two different versions of a Communication 430 course LibGuide. The first version of this guide had a longer, more visually complex navigation menu, with more course-related research information directly accessible through this menu. The second version had a shorter, less complex menu that offered less directly accessible information. Twenty-four of the 33 students enrolled in the class (73%) tested either one version or the other for usability in completing tasks that simulate course-related research assignments, ultimately indicating they found the longer navigation menu more usable. This paper may be the first to describe the engagement of students enrolled in a course in testing a LibGuide dedicated specifically to that course. As such, it will be of interest to many academic librarians and instructional design professionals.Inspired by increased interest among librarians from the 1970s onward in helping their patrons both access library resources and become information literate, many university libraries include research guides on their Web sites. With some exceptions, these guides are typically either course guides or subject guides -in other words, tailored to the research needs or assignments of an individual course, or to the research needs of a broad field of study. The content they present and architecture of how they present it may change accordingly. Though they are often created using the Springshare company's LibGuides software package, these guides are almost always designed or customized by individual librarians and tailored to individual courses and curricula at the university. Consequently, the questions of what to put on a guide and how best to arrange that material have driven an entire research agenda for the better part of a decade.A typical course-based information literacy (IL) guide, including those discussed in this study, is designed to assist students in finding information for their coursework. Most librarians, however, do not believe that simply creating a guide to do this is enough. Most librarians make some amount of effort to design their guides to be user-friendly, or, to use another word, usable. As defined by the International Standards Organization (ISO 9241-11:1998), usability is the "extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use" (International Standards Organization, 1998).1 A usable guide accordingly fulfills the goal of assisting students in finding information for their class in several ways, such as situating the user's coursework needs in a broader research process, placing searchable sources of information in a context that ties in to these needs, and offering guidance on how best to utilize these sources to find the most targeted, relevant, and valuable information relating to these needs. Design measures to address these needs can help maximize student ability to sea...