GIS has captured planning practice to an unprecedented degree, and this article on how it reconfigures and is configured by institutional context. The author inquires into GIS as a technology for incorporating knowledge into institutional use and includes five propositions: GIS's efficiencies in data processing allows it unprecedented facility and scope of analysis, its use increases alienation, its mimetic language furthers its role in planning, its logic appears rational—purposive, but it conceals an underlying normative logic, and its most profound effect (...) is on the mapper, and the alienating and normative character of GIS necessitate new modes of “social ground-truthing.” The author studies the southeast Los Angeles initiatives to demonstrate these propositions. This article compares two studies: one GIS-based, and the other based on participatory action research and discusses how GIS might be recontextualized into a technology for liberating democratizing processes. (shrink)