Issues in Identification and

Assessment of the highly gifted is complex. Differences in scores obtained on various instruments are much greater for this group than for any other population. Discrepancies have been found in excess of 100 points (Silverman & Kearney, 1992b)! By comparison, there is relatively little variation in scores from test to test for average and retarded children. The culprit is ceiling effects, which occur when the child's knowledge goes beyond the limits of the test. None of the modern individual and group tests have items of sufficient difficulty to assess the full strength of the abilities of highly gifted students (Silverman & Kearney, 1989; 1992a). A recent study compared IQ scores of 20 highly gifted children derived from both the Stanford