Score comparability of a state mathematics assessment across students with and without reading accommodations

This study investigated the factorial invariance of a fourth-grade state mathematics assessment across groups of general education students and students with learning disabilities with and without reading accommodations. Confirmatory factor analysis was used to assess the fit of a 2-factor model to each of the 3 groups. In addition to the overall fit of this model, several levels of constraint were investigated. Invariance across the 3 groups was supported for factor loadings and intercepts. However, invariance of the factor covariances across the general education group and the groups of students with learning disabilities was not supported. Because of the implications for aggregating reported scores, further research is needed into the relationship between the factors in the different groups.