Schulte, A. A. G., Elliott, S. N., & Kratochwill, T. R. (2001). Effects of testing accommodations on standardized mathematics test scores: An experimental analysis of the performances of students with and without disabilities . School Psychology Review , 30 (4), 527–547. https://doi.org/10.1080/02796015.2001.12086133

Students with disabilities received accommodations based on their individual needs. Each student without a disability was randomly assigned to receive a set of accommodations corresponding to one of the students with disabilities. Twenty different packages of accommodations were used, with the most common components being extended-time and read-aloud. All students completed one form of the test without accommodations and one form of the test with accommodations.

Eighty-six (86) grade 4 students participated. Forty-three (50%) of these students were identified with disabilities by the states of Wisconsin or Iowa (U.S.). These included students with learning disabilities, speech/language disabilities, and mild cognitive disabilities. All students were Caucasian with the exception of one African-American student, and 36 students were female and 50 students were male.

The TerraNova Multiple Assessment Battery (CTB/McGraw-Hill, 1997c) mathematics subtest was used as the dependent variable. This assessment is composed of three parts: Part One: Computation problems, simple word problems requiring single computation, and estimation skills; Part Two: Concepts and application skills; problems require a variety of strategies to arrive at solutions; Part Three: Constructed-response items in which students have to describe solutions and evaluate problem situations.

Both students with and without disabilities, as groups, experienced a beneficial effect from test accommodations. Although students with disabilities experienced a larger effect in the accommodated condition than did students without disabilities, the difference between groups was not significant. Students with disabilities profited more than students without disabilities on the multiple-choice items, but not the constructed response items. The accommodation package of extra time and read test items to student did not have a differential impact for students with disabilities when compared to students without disabilities. Students with disabilities receiving accommodation packages other than just extra time and read test items to student experienced a statistically significant and differential impact of testing accommodations on math scores. [See also Schulte, Elliott, & Kratochwill, 2000; Schulte, 2000]