During the past 20 years, international and bilateral assistance and funding agencies have become increasingly involved in evaluation activities in adult and nonformal education, especially in developing countries. The adult education field pioneered many approaches now advocated by specialists in program and project evaluation. Beginning in the 1920s and 1930s, United States agricultural extension specialists did extensive studies on farmer extension practices. In the 1950s and 1960s, international efforts began to build on some of the earlier agricultural extension concepts. Needs assessments, evaluation of adult education booklets, and evaluation of UNESCO adult education, literacy, and reading materials were all conducted. The UNESCO Experimental World Literacy Program conducted 11 projects in the late 1960s to mid-1970s that had built-in evaluation systems. During the 1970s and early 1980s, the governing bodies of most international organizations stipulated more evaluative efforts to provide data on the impact of various organizational activities. Such evaluation efforts sensitized project and program personnel in international agencies and in national governments to the need for participatory evaluation specifically to improve projects and programs. (A list of references is appended.) (YLB)