Summary. Librarians at Springfield College conducted usability testing of Endeavor's federated search tool, ENCompass for Resource Access. The purpose of the testing was to make informed decisions prior to customizing the look and function of the software's interface in order to make the product more usable for their patrons. Protocol, or think-aloud, analysis was selected as a testing and analysis method. Subjects from the general college community were recruited and given a list of tasks to perform on ENCompass, and they were asked to speak all of their thoughts out loud as they worked. Upon analyzing the test results, researchers found that subjects' problems fell into certain categories, such as unfamiliarity with terms or navigation from screen to screen. The researchers were able to use their findings to recommend extensive revisions to the interface, which improved usability for this library's patrons.