Despite the importance of computerization to data use, little is known about the work of a central office when it comes to preparing for and implementing computer data systems. This study illuminates such work by drawing upon interviews and observations collected in three school districts over 11 months. We describe how central offices thought about, prepared for, and implemented computer data systems. We find that district efforts may be undermined by overly simplistic stances toward technology and planning. Accordingly, we discuss the ways in which central offices might rethink assumptions, strategies, and bureaucratic structures around data systems.