SUBTEST AND COMPOSITE SCORE COMPARISONS FOR THE DIAGNOSTIC ACHIEVEMENT BATTERY 2ND-EDITION

Interpretation of the variation in an individual student's subtest and composite scores on the Diagnostic Achievement Battery (second edition) requires the comparison of many values. Although values needed for significance when one is making pairwise comparisons are provided in the test manual, this method does not control adequately for experimentwise error rate. That is, if five comparisons are made, and each is tested at the .05 level, the error rate for the combination of five comparisons is much higher than .05. Use of the Bonferroni correction when one is comparing each score to the mean score is one method that controls the overall error rate during interpretation of an individual's test scores. With this method, the differences required for significance when one is comparing an individual's subtest score to the mean of all the subtest scores were computed at the .05 and .01 levels in accordance with the procedure presented by Davis and modified by Silverstein. Additionally, the same values when one is comparing Composite scores for an individual were computed, An example of the use of the technique is provided.