This qualitative study describes collaborations between academic librarians and faculty in education-related disciplines involving evidence-based practice (EBP), an approach that combines the best available research with the professional's experience and expertise. The authors analyzed narratives of academic librarians and their educator partners using the lens of cultural historical activity theory (CHAT), a sociocultural idea about the interaction between human beings and their material and social environment. The authors identified four themes in the participant narratives: EBP as research-based practice; EBP as the librarian's tool for initiating collaboration; varying degrees of EBP-related collaboration; and epistemological tensions involving the application of EBP in education. These findings illustrate the constructed nature of authoritative knowledge as described in the Association of College and Research Libraries (ACRL) Framework for Information Literacy for Higher education.