Abstract
The articles in this special issue make two important contributions to our understanding of the impact of accommodations on test score validity. First, they illustrate a variety of methods for collection and rigorous analyses of empirical data that can supplant expert judgment of the impact of accommodations. These methods range from internal analyses of reliability, differential item functioning, and factor structure to different ways for comparing score means from accommodated and non-accommodated assessments and ways of incorporating external criteria in assessing changes in validity. Equally important, these articles add significantly to our knowledge of the impact of specific reading accommodations for varying groups of students with disabilities. The accommodations reported included large print and Braille tests for blind and visually impaired students, segmented text for students with specific learning disabilities, and audio presentation of text for students with a variety of disabilities. The results reported are mixed, indicating some support for the validity of scores from accommodated assessments and also raising some questions for further exploration. Further meta-analytic studies are needed to sort out often conflicting results within and across different studies of reading accommodations.