Effects of Testing Accommodations on Standardized Mathematics Test Scores: An Experimental Analysis of the Performances of Students With and Without Disabilities

The study examined the effects of testing accommodations on the mathematics test scores of a sample of 86 fourth-grade students, which included 43 students with disabilities (SWD) and 43 students without disabilities (SWOD). This study featured a 2 × 2 × 2 mixed design in which all participants were tested under a treatment condition (i.e., accommodations during test) and a control condition (i.e., no accommodations during test) using equivalent forms of a mathematics test used in many statewide assessment programs. Testing conditions were randomized to counteract possible order effects. Primary analyses indicated that SWDs experienced a larger effect in the accommodated condition than did SWODs. The SWDs profited more than SWODs on the multiple-choice items, but not on the constructed-response items. Similar numbers of students with and without disabilities experienced either (a) a beneficial effect in the accommodated test condition resulting in an increased proficiency level, (b) a detrimental effect in the accommodated test condition resulting in a decreased proficiency level, or (c) a minimal effect resulting in no change in proficiency levels. These results and several limitations to the study are discussed along with implications for practice and future research.