Abedi, J., Leon, S., Kao, J., Bayley, R., Ewers, N., Herman, J., & Mundhenk, K. (2011). Accessible reading assessments for students with disabilities: The role of cognitive, grammatical, lexical, and textual/visual features (CRESST Report No. 785). University of California, Los Angeles, National Center for Research on Evaluation, Standards, and Student Testing. https://cresst.org/publications/cresst-publication-3156/
Also located on ERIC https://eric.ed.gov/?q=ED520492
In this report, authors investigated the role that certain features of reading test items (cognitive, grammatical, lexical, textual/visual) play in causing reading test items to function differently for students with and without disabilities.
Participants were students in grade 8 in three unidentified states (U.S.). Students with (n=28,812) and without disabilities (n=257,211) were included in the analyses.
The dependent variable was scores on nine reading assessment forms across the three participating states. Assessments included multiple-choice, extended-response, and field test items. External raters also rated the accessibility of items.
Results indicated that students with disabilities perform lower on standardized tests than students with no identified disabilities in both state and national assessments. DIF and discriminant analysis procedures revealed that some accessibility features had more impact on reading than other features, and some of these features had more differentiating power than others between students with and without disabilities. Features that had the highest level of impact on the performance of students with disabilities (i.e., their performance was lower): depth of knowledge, complex verbs, subordinate clauses, % of unique words compared to total words at passage level, words with more than 7 letters, point size, font change, and unnecessary visuals. Discriminant analyses suggested that textual/visual features and lexical features have the highest level of discrimination power between students with and without disabilities. Limitations of the study were reported, and future research directions were suggested.