McKevitt, B. (2000, June). The use and effects of testing accommodations on math and science performance assessments [Paper presentation]. Council of Chief State School Officers (CCSSO) National Conference on Large-Scale Assessment, Snowbird, UT, United States.

Students with disabilities completed half of the tasks with accommodations recommended by teachers on IEPs or AACs (Assessment Accommodations Checklist). They completed the remaining items under standard conditions. Students without disabilities were randomly assigned to one of three groups: 1) no accommodations provided, 2) three common accommodations provided on half of the tasks (reading and paraphrasing directions [read-aloud directions], providing verbal encouragement, giving extra time [extended-time]), and 3) accommodations recommended by students' teachers provided on half of the tasks.

Participants were 218 fourth-grade students from urban, suburban, and rural school districts in Wisconsin (U.S.). 73 students had been diagnosed with a disability (36% of sample; learning disability, emotional disturbance, cognitive disability, speech/language, other health impairment, autism) and were receiving special education services. 102 female and 116 male students were included. 89.9% were white, 6.9% were African American, 1.8% were multi-ethnic, .9% were Hispanic, and .5% were Native American.

Two sets of performance assessments (one for math and one for science) were developed by master teachers from the Wisconsin Student Assessment project in 1993-95. These assessments require students to draw on their full range of knowledge of a content area to produce a response.

Overall, testing accommodations had medium to large positive effects for 78.1% of students with disabilities and 54.5% of students without disabilities. Small or zero effects were found for 9.6% of students with disabilities, and 32.3% for students without disabilities. On average, the resulting individual effect size when comparing accommodated scores to non-accommodated scores was .88 (sd=.78) for students with disabilities, .44 (sd=.61) for students without disabilities who received the standard package , and .45 (sd=.79) for students without disabilities receiving teacher-recommended accommodations. The performance of students with disabilities under the accommodated condition was slightly lower than students without disabilities, while the performance of students with disabilities without accommodations is much below the average performance of other students.(see also Elliott et al., 1999; McKevitt et al., 1999; McKevitt et al., 2000; Elliott, 2001)