Kettler, R. J., Niebling, B. C., Mroch, A. A., Feldman, E. S., & Newell, M. L. (2003). Effects of testing accommodations on math and reading scores: An experimental analysis of the performance of fourth and eighth grade students with and without disabilities (WCER Working Paper No. 2003–7). Wisconsin Center for Education Research, University of Wisconsin-Madison. https://wcer.wisc.edu/publications/workingPapers

Downloadable from webpage: https://wcer.wisc.edu/publications/abstract/wcer-working-paper-no.-2003-7 ​

Participants with disabilities were assigned accommodations based on their IEPs. Participants without disabilities were paired with students with disabilities. Each pair was tested under the accommodation condition during which both students in the pair received the same set of accommodations.

A total of 196 students, with 118 grade 4 and 78 grade 8 students comprising the sample. Forty-nine of the fourth-grade students and 39 eighth grade students met disability criteria in the state of Wisconsin (U.S.; 45% of total sample).

Two math subtests and two reading subtests from research editions of the TerraNova Multiple Assessment Battery were used to assess participants' achievement levels.

Among fourth grade students, accommodations provided a larger effect for students with disabilities than students without disabilities on both the mathematics and the reading tests. Among eighth grade students, the effects of testing accommodations depended on the test content (math versus reading). The effects of testing accommodations on the math tests were somewhat higher for students with disabilities than for students without disabilities. Conversely, the effects of testing accommodations on the reading tests were slightly lower for students with disabilities than for students without disabilities.