Fig. 1.

Practice effects by cognitive domain. Practice effects are presented in standard deviation (SD) units for each cognitive ability composite. Bars represent practice effects calculated from unadjusted scores, scores adjusted for education, and scores adjusted for age 20 AFQT. Asterisks indicate significant practice effects (P < .05) as determined by permutation testing. Unadjusted practice effects are likely to be biased upward due to significant group differences in age 20 AFQT and education, thus adjusted scores reflect more accurate estimates. Abbreviation: AFQT, Armed Forces Qualification Test.