Witmer, S. E., & Marinho, N. (2024). Extended time test accommodations: Does use correspond to score comparability for students with disabilities deemed in need ? Psychology in the Schools , 61 (11), 4175–4188. https://onlinelibrary.wiley.com/journal/15206807

Extended time on a math test was studied as an assessment accommodation. This accommodation allowed students with disabilities to have up to 90 minutes to complete a test block that typically had a 30-minute time limit.

Students in grade 8 who took the 2017 National Assessment of Educational Progress (NAEP) mathematics test participated. Three groups were compared: students with disabilities who were eligible for extended time but did not use it (N=1010), students with disabilities who were eligible and used extended time (N=500), and a reference group of randomly selected students without disabilities who completed the test within standard time limits (N=1010). Most students with disabilities had specific learning disabilities or other health impairments.

Student scores and psychometric characteristics on a 15-item block of the NAEP mathematics test were analyzed using a Poly-SIBTEST procedure to determine differential item functioning (DIF). Process data from the digitally-administered test provided information on item response times and allowed researchers to identify which students used extended time versus those who did not. Score comparability was measured by examining whether significant DIF existed between the various groups.

Score comparability was evident regardless of whether students with disabilities deemed eligible for extended time used the accommodation. No items displaying significant DIF were found when comparing students with disabilities who did not use extended time to students without disabilities. When comparing students with disabilities who used extended time to students without disabilities, only one item showed DIF slightly favoring the extended time users.