Examining equivalence of accommodations on a statewide elementary-level science test

This study examined the extent to which the underlying factor structure of the 2005 South Carolina Palmetto Achievement Challenge Tests (PACT) in science for grades 3, 4, and 5 was equivalent for students who were administered the test in a regular (standard) or accommodated form. Three accommodation groups were of interest: students who received any testing accommodations, students who received any testing accommodations excluding those for whom setting was the only accommodation provided, and students who received the oral administration accommodation. Each accommodation group was compared to a matched sample of the regular group. It was found that the science test for a given grade level is appropriately described by the factor model for regular and accommodation groups. Results indicated that the factor structure, factor loadings, and error variances of the science test were similar across the regular and accommodation groups.