Effects of Testing Accommodations on Math and Reading Scores: An Experimental Analysis of the Performance of Students With and Without Disabilities

Ryan J. Kettler, Bradley C. Niebling, Andrew A. Mroch, Elizabeth S. Feldman, Markeda L. Newell, Stephen N. Elliott, Thomas R. Kratochwill, Daniel M. Bolt

Research output: Contribution to journalArticle

10 Scopus citations


This study examined the effects of testing accommodations on the mathematics and reading test scores of a sample of 119 fourth graders and 78 eighth graders. The sample included 49 fourth-grade students diagnosed with a disability and 39 eighth-grade students diagnosed with a disability. The study used a 2 (Disability Status) x 2 (Testing Condition) ¥ 2 (Grade) ¥ 2 (Test Content Area) ¥ 2 (Order) mixed design. All students were tested under two conditions (i.e., accommodated or nonaccommodated) on equivalent forms of research editions of mathematics and reading tests from an achievement test used in many statewide assessment systems. Testing conditions were randomized to control for potential order effects. Results indicate that fourth-grade students with disabilities (SWD) benefited from testing accommodations more than students without disabilities (SWOD); this differential benefit was greater on the reading tests (effect size for SWD = .42, effect size for SWOD = .13) than on the mathematics tests (effect size for SWD = .46, effect size for SWOD = .27). Furthermore, a higher percentage of SWDs improved at least one proficiency level than SWODs. Both SWDs and SWODs in eighth grade gained slight benefits from the testing accommodations. More eighth-grade SWDs improved at least one proficiency level on the reading tests, but more SWODs improved at least one proficiency level on the math tests. The article discusses implications of these findings, limitations of the study, and directions for future research.

Original languageEnglish (US)
Pages (from-to)37-48
Number of pages12
JournalAssessment for Effective Intervention
Issue number1
StatePublished - Oct 2005
Externally publishedYes


ASJC Scopus subject areas

  • Education
  • Developmental and Educational Psychology
  • Health Professions(all)

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