The purposes of this research were to first examine the evidence regarding the factor structure of educational achievement tests in the context of two theoretical models of cognitive ability (psychometric g and mutualism) that have been proposed to explain this structure as well as the underlying processes that may be responsible for its emergence in dimensionality studies. Then, the factor structure underlying a sample of the standardized educational achievement tests used by California in its statewide school accountability program was compared to those emerging from a selection of behavioral and personality assessments. As expected, the educational achievement tests exhibited a strong and uniformly positive manifold resulting in greater unidimensionality as evidenced by a dominant general factor in bi-factor analysis then either the personality or behavioral assessments. The implications of these structural differences are discussed with respect to the two theoretical perspective as well as in the context of formative and summative educational inferences in particular, and the school accountability and reform movement in general.