This study assessed the adjustment of the Rasch model concerning unidimensionality of Raven's Colored Standard Progressive Matrices. Four hundred and forty-one (441) elementary school children, of both genders, attending first to fourth grade were investigated. Considering that residuals may be enough to violate the intrinsic unidimensionality of the items, residual principal component analysis was used to assess the possibility of this violation. Items with higher factorial loading relating to the positive and negative dimensions on the first factor were selected, in respect to the test as a whole and to each subset in particular. These items were re-analyzed with the Rasch model within each data group. Then the positive and negative factor measures were correlated. Results suggested the possibility of other dimensions besides those extracted by Rasch model based on the test and subset B, though the correlation coefficients of the other subsets were close to rejection.
Rasch model; unidimensionality; Raven's test
