e instrument was administered to each subject twice with an interval of three weeks between administrations. The resulting test retest reliability coefficient was r = .91, which "is sufficiently high to indicate that the individual IQ scores man be meaningfully interpreted" (Kellogg and Morton, 1978, p. 22). The standard error of the measurement ("a statistic permitting the construction of a band of error around a test score") for the Revised Beta Examination was 4.6 (Kellogg and Morton, 1978, p. 22). This statistic "means that the chances are approximately two out of three that an examinee's 'true' Beta II IQ is within 4.6 points of the obtained IQ" (Kellogg and Morton, 1978, p. 22). A "true" test score is considered to be "the average score an examinee would obtain if tested a large number of times, and if the effects of practice, fatigue, and the like could be eliminated" (Kellogg and Morton, 1978, p. 22
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