Koretz, D. (1997). The assessment of students with disabilities in Kentucky (CSE Report No. 431). University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing (CRESST), University of California, Los Angeles. https://cresst.org/publications/cresst-publication-2803/

The most frequently used accommodations were grouped into four major classes: dictation, oral reading, rephrasing, cueing. Data were examined on these accommodations singly and in combination along with actual test performance.

Performance data were analyzed from students in grades 4 and 8 from across the Commonwealth of Kentucky (U.S.) who completed tests in the statewide assessment program. This extant data set contained 142,844 students' scores, of whom 11,159 were students with disabilities.

Two major dependent variables were used: the frequency with which an accommodation was used and the performance on the statewide test in reading, math, social studies, and science when the accommodation was used.

In grades 4 and 8, accommodations were frequently used (66% and 45%, respectively). When students with mild intellectual disabilities in grade 4 were provided dictation with other accommodations, they performed much closer to the mean of the general education population, and above the mean in science. Similar results occurred for students with learning disabilities. For students in grade 8, the results were similar but less dramatic. Using multiple regression to obtain an optimal estimate of each single accommodation and then comparing predicted performance with the accommodation to predicted performance without the accommodation, dictation appeared to have the strongest effect across the subject areas of math, reading, and science, as well as across grade levels. This influence was significantly stronger than that attained for paraphrasing and oral presentation, respectively. (See also Koretz, 1997; Koretz & Hamilton, 2000)