Exploring Factors Shaping the Use and Effectiveness of Accessibility Tools in Large-Scale Digital Language and Mathematics Assessments

This study examines the use and effectiveness of built-in accessibility tools (ATs) in large-scale digital language and mathematics assessments using population-level data from 125,000 fourth- and eighth-grade L1-speaking students with and without registered special educational needs (R-SEN). Multilevel analyses of log data and self-reports examined group differences and associations with achievement. AT use varied by domain, grade, and R-SEN status. In fourth grade, non-R-SEN students more often used linguistic tools in language, whereas R-SEN students more often used dictionaries and used calculators more intensively in mathematics. By eighth grade, most group differences had diminished, except for calculator use. Classroom familiarity, motivation, and perceived usefulness were weakly related to AT use. Only glossaries and calculators were positively associated with performance, whereas intensive use of linguistic tools was associated with lower performance, particularly among R-SEN students. Overall, effective accessibility depends on alignment between tool function, task demands, instructional context, and learner development.