THE ROLE OF HIGHER-ORDER COGNITIVE-ABILITIES AS MEDIATORS OF DEFICITSIN ACADEMIC-PERFORMANCE

The questions in this study were three-fold. The first question, sugge sted by the work of Das and Naglieri (e.g., Naglieri & Das 1987, 1988) , addressed the hypothesis that a higher-order structure underlies per formance on a battery of cognitive tests. The second question, concern ed with external validity, addressed how well the higher-order cogniti ve ability factors predict two criterion-related measures of ability, Academic Achievement and Word Skills. The third question, also concern ed with external validity, addressed whether differences between stude nts classified as low or normal in reading achievement were mediated b y individual differences in the higher-order ability factors. That is, do the hypothesized higher-order cognitive abilities play a mediating role in predicting deficits in academic achievement and reading compe tence? Structural equation modeling techniques were used to test these research hypotheses on a stratified random sample of 135 third grade students. The first stratum contained a random selection of 69 student s classified as low in reading achievement based on the Chapter I enti tlement assignments made by the school district the year prior to the study and the second stratum contained 66 students selected from the n ormal achieving population. The results showed that (a) two higher-ord er factors, Planning/Attention and Successive Processing, explained th e relations among six lower-order ability constructs, (b) the higher-o rder ability factors predicted individual differences in the two crite rion measures of Academic Achievement and Word Skills, and, (c) low ac hieving students showed significant deficits only in the two higher-or der factors, suggesting a mediating role for the cognitive skills repr esented by the higher-order factors.