This one-page abstract summarizes results of a final report of a federally funded research project titled, "Research Integration Project: Analysis and Review of Research on Least Restrictive Environments for Handicapped Learners." The goal of the project was the review, analysis, and interpretation of research on the concept of "least restrictive environment." The paper defines the term and examines the legal and legislative background which is based on the assumption that removal from the regular classroom setting potentially abrogates a student's rights. Results of evaluation of various administrative arrangements indicate that differences between regular and self-contained special education classroom environments are not typically as large as differences in classroom characteristics such as curriculum, teacher-student ratio, and teacher qualifications. The project also reviewed those variables related to the design of instruction and the educational environment encompassing factors related to both academic achievement and social outcomes. It is concluded that the amount of time a student is integrated is but one variable which may, or may not, have an impact on student achievement and/or social growth. (DB)