When scholars seek to measure the "effectiveness" of rights, they are usually trying to understand the extent to which they affect the practices of organizations. Rights live in many placesâ??in the bodies (courts, agencies and legislatures) that produce them, in the minds of the activists who mobilize them, in the broader public and in the popular cultureâ??but it is principally within organizations that rights are materialized, turned into tangible changes in social practices. Thus in this project we seek to 1) create a conceptual framework that captures the protean nature of rights, 2) describe the varied patterns by which organizations respond to rights, and 3) measure how those organizational responses correlate with outcomes. This paper takes a few modest steps toward these goals. We begin with a general framework for understanding rights and organizational change. We develop some basic hypotheses about organizational response to rights, drawn from political science, neo-institutionalist sociology, and organizational theory. We probe these hypotheses using original qualitative and quantitative data drawn from a study of organizational responses to the access provisions of the American with Disabilities Act (the "ADA") and its state analogues. ..PAT.-Unpublished Manuscript [ABSTRACT FROM AUTHOR]