The five papers in this symposium address several key issues included in evaluation research. In "Designing State Vocational Rehabilitation Agency Evaluation Research", Stanford E. Rubin discusses the importance of practitioner involvement in the development of research questions and plans and introduces three basic models of evaluative research. Brian Bolton's paper, "Problems in Measuring Outcomes in Rehabilitation Research Projects", comments on such issues as the criterion problem in rehabilitation counseling, measures of client outcome, and procedures for quantifying psychometric change. Problems encountered in conducting large scale evaluation studies are discussed in the context of a Services Coordination Project in Richard Roessler's presentation, "Issues in Initiating Large Scale Rehabilitation Research." Reed Greenwood reviews the need for expanding the parameters of evaluative research to a system approved at both mezzo and macrosystem levels in his paper, "Assessment of External Effects in Rahabilitation Research." Finally, Jerold D. Bozarth, in "Reactions on Evaluation", discusses the differences between research and evaluation. (RC)