Date of Award


Document Type


Degree Name

Doctor of Psychology (PsyD)



First Advisor

Dasen Luo, Ph.D.

Second Advisor

Krzysztof Kaniasty, Ph.D.

Third Advisor

Donald U. Robertson, Ph.D.


Generalized latent variable modeling was used to examine the relationship between working memory and academic achievement. The contributions of two working memory mechanisms that are involved in a wide variety of working memory tasks, namely short-term storage (STS) and generalized attention control (GAC) were examined. The contributions of two working memory mechanisms that are specific to two well-established measures of working memory (Digit Span and Letter-Number Sequencing), namely Backward Ordering (BO) and Mental Sorting (MS), were also examined. The contribution of these working memory mechanisms as a whole was additionally evaluated, and compared to the contribution of traditional measures of intelligence. Mechanisms that are common across multiple working memory tasks (specifically, STS and GAC) were found to make an important contribution to both intelligence and achievement, while task-specific factors (BO and MS) were not. Furthermore, in this study the combined working memory factors were clearly better predictors of achievement than traditional measures of intelligence. At the same time, results of this study indicate that both of these traditional measures of intelligence make significant and unique contributions to academic achievement above and beyond those of the working memory factors. The most unique aspect of this study was the examination of the relationship between independent latent working memory factors and a latent achievement factor. Unlike previous studies that did not differentiate between the role of storage and the role of attention control, this study was able to provide more precise information about the nature of working memory’s contribution. Thus, it was possible to discern that the general factors of GAC and STS both made substantial unique contributions and that the contributions of the more specific mechanisms were much lesser. The theoretical and practical implications of these findings are discussed.