Racial factors in personnel selection procedures and the performance of racial and socio-economic groups on a testing instrument widely used in personnel selection and in public schools are discussed. The study questions whether individual test items are relatively easier for one racial group than for another, and whether there is a relationship between test performance and socio-economic status. A description of the instrument, subjects, method, and a careful analysis of the data is included. Considerable interest has been aroused by this study, perhaps because it is the first project of its kind to be undertaken. (TA)