Engelhard, G., Jr., Fincher, M., & Domaleski, C. S. (2011). Mathematics performance of students with and without disabilities under accommodated conditions using resource guides and calculators on high stakes tests . Applied Measurement in Education , 24 (1), 22–38. https://doi.org/10.1080/08957347.2010.485975

Students with and without disabilities were randomly assigned to one of three conditions: resource guides, calculators, and standard administration.

Students with and without disabilities from 145 schools across the state of Georgia (U.S.) in grades 3 and 4, and students from 89 schools across Georgia in grades 6 and 7. The grades 3 and 4 sample included 947 students, and the grades 6 and 7 sample included 997.

The dependent variable was scores on the Georgia Criterion-Referenced Competency Tests (CRCT) in mathematics, a test used to determine how well students have acquired skills and knowledge in the state's math curriculum.

This study looked at the performance of students with disabilities under accommodated and nonaccommodated conditions, students without disabilities in accommodated and nonaccommodated conditions, and compared the performance of students with and without disabilities on accommodated and nonaccommodated conditions. Results showed that resource guides were not an effective accommodation for students with or without disabilities. Calculator use seemed result in a small increase in the mean scores of students with and without disabilities in both age groups in most cases. No support was found in this study for the interaction hypothesis (no evidence that the accommodations were reducing construct-irrelevant barriers to the achievement of students with disabilities). Overall, students without disabilities experienced larger gains in scores than students with disabilities. Limitations of the study were reported, and future research directions were suggested.