it is not easy to discern a priori, to what extent any given program will mitigate the risks and realize the benefits. Evaluation of public involvement programs is therefore essential in order to establish a data base on which to build more intensive public involvement programs. Recent trends in public opinion polls suggest that public perceptions of the economy, energy situation and the environment have changed from optimism about an unlimited future towards a new sense of lowered expectations and a limited future. Scientific research and technological developments are perceived as mixed blessings, and the public seems unwilling to sacrifice the environment for high economic or energy growth. Although energy use is expected to increase, the rate of increase is not easily predicted, due to a number of variables which influence the rate of growth. In general, a trend away from centralization of institutions and deci- sion making in the U.S. is evident. States are assuming more power, communities and neighborhoods are increasing their influence and control, and a militant new regionalism is likely to emerge in the 1980s. There is a growing jurisdictional diversity in approaches to problem solving (including those related to energy), reflected in increasing use of referenda or initiative process. There is also a trend toward a multioption society, rather than an either-or society, reflected in the increasing interest in "appropriate scale" technologies rather than technologies based on economies of scale. At present it is not known whether the SPS will ultimately be acceptable to the public; what is certain is that public acceptance is an essential part of SPS development. Although these studies have found trends in American society which suggest public acceptance of SPS will not be easily obtained; the stability, longevity, and potential influence of these trends with respect to SPS are not clear. Furthermore, the public's position with respect to SPS is expected to be volatile thoughout the development process as more information becomes available from R&D efforts. Fears may be quieted and then refired as the proximity to a go/no decision becomes closer. The political climate of "energy crises" may result in changes of opinion or new concerns. Assessing and obtaining public acceptance are, therefore, long-term processes, requiring a continuing program of public involvement.