In an environment in which libraries need to demonstrate value, illustrating how the library contributes to student learning is critical. Gathering and analyzing data to tell the library's story as well as identify areas for improvement require commitment, time, effort, and resources--all components of a culture of assessment. This paper presents the results of a survey designed to understand what factors facilitate the development of a culture of assessment of student learning in academic libraries and what factors may hinder it. Unlike previous research in this area, which has focused on case studies and surveys with nonrepresentative samples, the authors conducted a systematic survey of academic libraries at four-year institutions in the United States and achieved a 42 percent response rate. The results suggest certain factors are highly associated with a culture of assessment and provide guidance to administrators and front-line librarians working to build such a culture.