To measure the extent of racial or sexual discrimination in resource allocation programs of the National Institute of Mental Health (NIMH), the concept of difference indicators was adopted. The difference indicator is a quantitative index that expresses the relationship between actual and expected quantities of any given trait or object. In the context of equal treatment, the notion of expected number would refer to the number of minority persons expected to possess a particular characteristic if race or sex were not related to having that characteristic. The index may yield a value of zero, indicating equal treatment, a negative value, indicating minority underrepresentation, or a positive value, indicating minority overrepresentation in a given program. As applied to NIMH, the difference indicator concept yielded a set of indices for several factors. One index compared total resources allocated to minorities to the amount that would have been allocated to them had they received resources in proportion to their number in the relevant population. Another index compared the proportion of minorities being studied in NIMH-funded research to the proportion of minorities in the national population. The difference indicators model provides a tool through which organizations can plan, implement, and evaluate programs to eliminate institutional racism. (AuthorMJL)