Issues surrounding the concept of nonbiased assessment, particularly with economically disadvantaged minority students, are analyzed. The legal requirements are focused on thorough discussion of litigation and legislation. The second section explores research on the use of the Wechsler Intelligence Scale for Children-Revised (WISC-R). Research touches on the many definitions of bias, construct validity/content bias, item bias, atmosphere bias, and bias in test use. The author states that conclusions regarding the validity and bias of the WISC-R with minorities vary depending on the definition of bias. A definition is proposed based on the outcomes of test use for the individual. Prerequisites to nonbiased assessment are identified, including good fundamentals and ethical practices, clarification of purpose, and multifactored assessment. Research on the System of Multicultural Pluralistic Assessment are reviewed, followed by a discussion of assessment of adaptive behavior with mentally retarded persons. Requirements of P.L. 94-142, (the Education for All Handicapped Children Act) that the child's sociocultural background and primary language be taken into account are considered. The continuing problem over defining mild mental retardation is examined. The author concludes by emphasizing the importance of multifactored assessment and of viewing nonbiased assessment as a process rather than a specific number of instruments. (CL)