The contribution of multiple theories of the policy process stems, in part, from the identification of alternative concepts and relations that provide distinct—though often partially overlapping—explanations of (and predictions about) policy development. Thus the competing theories single out alternative concepts as critical to the policy process, and specify widely different hypotheses for test. When theory-building is at a rudimentary level, as is generally the case for the study of the policy process, the alternative theories may provide enriching supplemental insights and hypotheses that, if confirmed, lead to better theory. In that spirit, this article provides some illustrations of the application of alternative theories to an ongoing policy dispute over adoption and development of the Waste Isolation Pilot Plant (WIPP) as a testing and storage facility for defense nuclear wastes. My focus is on how the alternative theories emphasize different sets of concepts (and therefore data) and hypotheses, and on some of the implications for research design. These comments are based on my own preliminary research on the WIPP issue, and are meant to be illustrations and suggestions, rather than conclusions, about the policy process regarding the WIPP.