The document contains the final report of a project to determine the factors that account for disproportionate representation of minority students in special education programs, especially programs for mentally retarded students; and to identify placement criteria for practices that do not affect minority students disproportionately. Chapter 1 looks at six potential causes of disproportionate placement of minorities in educable mentally retarded (EMR) programs: legal and administrative requirements, characteristics of students, quality of the instruction received, possible biases in the assessment process, characteristics of the home and family environment, and broader historical and cultural contexts. Chapter 2 describes characteristics of EMR students, then reviews the historical origins of special education in America with attention to the role of the standardized intelligence test for identification and placement of mentally retarded students. A third chapter is split into two sections--one on the issues surrounding the instruments that comprise a comprehensive battery for assessing a child who is unable to learn normally in the classroom, and the other on an ideal assessment process in which the comprehensive assessment would be embedded. Chapter 4 considers the components of effective education programs for EMR students and reviews three approaches to instruction (the separate class structure, the resource room, and the teacher consultant model). A final chapter lists recommendations for improvements in special education referral, assessment, and placement procedures and instructional practices. More than half the document is comprised of six background papers with the following titles and authors: "Biological and Social Factors Contributing to Mild Mental Retardation" (J. Shonkoff); "Classifying Mentally Retarded Students--A Review of Placement Practices in Special Education" (W. Bickel); "Testing in Educational Placement--Issues and Evidence" (J. Travers); "Effects of Special Education Placement on Educable Mentally Retarded Children" (K. Heller); "Some Potential Incentives of Special Education Funding Practices" (S. Magnetti); and "Patterns in Special Education Placement as Revealed by the OCR Survey" (J. Finn). (SB)