Despite the growing volume of research on data use systems or data use activities in which teachers engage, micro-process studies--investigations of what teachers and others actually do under the broad banner of "data use" or "evidence-based decision making"--remain substantially underdeveloped. Starting with a review of the extant research on teachers' data use practice in workplace and professional development contexts, this article argues for a more conceptually robust, methodologically sophisticated, and extensive program of micro-process research on data use that also anticipates the ways in which local practice both instantiates and constructs institutional and organizational structures, processes, and logics. (Contains 3 notes.)