Legal, professional, and historical issues are examined in the report on minority group representation in special education in New Jersey. The historical and legal background traces the controversy over the use of IQ tests with minority children and notes court rulings citing overrepresentation of minority students in classes for the mildly retarded. Results of a statewide survey of school districts report the ethnic composition of their pupils in 17 classification (handicapping) conditions and five ethnic categories. Data indicate a disporportionate representation of Blacks and Hispanics in the educable mentally retarded category. Psychometric, genetic, socioeconomic status, and conceptual considerations are explored. Among 23 conclusions listed are that the courts have sustained the notion that disproportionate impact is sufficient to prove bias in practice, thus indicating that a disproportionate number of Blacks in EMR classes is racially discriminatory; that the eventual resolution of the IQ issue may best be accomplished through political efforts; and that the concept of mild mental retardation, as applied throughout the country, is arbitrary and invalid. (CL)