The aim of this study is to find validity evidence in the Scholastic Aptitude Test (PAA; Spanish acronym) of the University of Costa Rica (UCR) based on its internal structure. The construct measuring of this test presents two hypotheses for its structure: the one-dimensional and two-dimensional. For both guesses the stated goal was reached. For the one dimensional hypothesis an exploratory factor analysis (EFA) showed that the first factor explained a 23% of the variance of the PAA´s items while the second factor was only able to explain a 2.8%. Then, a confirmatory factor analysis (CFA) showed that this hypothesis is acceptably consistent with data. In terms of the two-dimensional hypothesis, the EFA Promax rotation displayed the association of factors to the suggested dimensions for the construct; in addition, the CFA associated with this hypothesis also showed a good fit. These results provide to the PAA developers team a theoretical support to make the Test´s psychometric analysis based on either position proposed on the structure of the evaluated construct.

Keywords: Scholastic Aptitude Test, one-dimensional, reasoning, verbal context, math context, tetrachoric correlation, Confirmatory Factor Analysis