The purposes of this study were: (a) to check the validity of the Peabody Picture Vocabulary Test (PPVT) and the Animons (1) Quick Test (QT) against the Wechsler Intelligence Scale for Children (WISC); (b) to ex amine the interrelationship of scores on the Gray Oral Reading Test, Spache's Diagnostic Reading Scales, and an informal reading inventory; and (c) to examine the consistency of discrepancy scores used to classify students as non-disabled, disabled, and seriously disabled readers. It was found that both the PPVT and the QT were significantly related to the WISC, but some group comparisons and many individual scores varied greatly. The tests of reading performance were also highly vulnerable. Therefore, the discrepancy scores between potential and performance, as measured by these instruments, were not consistent. The authors submit that the whole idea of assigning students to various types of reading programs on the basis of their discrepancy scores is open to serious question. THE NATION has recently turned its attention to the goal of having all its children reading up to a level commensurate with their potential in this decade. To begin dealing with this goal will require that easy-to-use and efficient instruments and techniques be put into the hands of teachers to help them determine which children are not reaching their potential. Presently, it is a fairly common practice in organizing for reading in struction to compute discrepancy scores between children's potential and performance and assign those children certain types of reading programs according to the amount of discrepancy. For ex ample, children who show no appreciable dis crepancy are placed in developmental programs, children who are disabled are placed in corrective programs,, and children who are seriously disabled are placed in remedial programs. To group students for instructional purposes on the basis of discrepancies between their poten tial and performance,, the teacher must have the following: (a) a valid and reliable test of in tellectual potential; (b) a valid and reliable test of reading achievement; (c) a rational way to compute reading expectancy; and (d) a rational set of criteria to use as classifying agents.