Trammell, J. K. (2003). The impact of academic accommodations on final grades in a postsecondary setting . Journal of College Reading and Learning , 34 (1), 76–90. https://doi.org/10.1080/10790195.2003.10850157

One or more academic accommodations was provided throughout the academic year: for exams, additional time to complete the tests and testing in a separate room; and for classroom and coursework, audio recordings of class lectures and course texts ("books on tape").

The sample consisted of 61 postsecondary students with disabilities who attended a liberal arts college in Virginia (U.S.).  The participants were divided into three categories: (a) students with Attention Deficit Disorder (ADD), (b) students with learning disabilities (LD), and (c) students with both ADD and LD.

Participants' end-of-term grades were compared and contrasted. The purpose was to examine whether postsecondary students with learning disabilities (LD) and/or Attention Deficit Disorder (ADD) experienced a differential increase in end-of-term grades when they used academic accommodations required by the Americans with Disabilities Act.

The impact of special accommodations on the subgroups revealed a significant improvement in grades for students with ADD and students with LD and ADD, but a drop for students with LD only. Students with ADD and ADD and LD experienced an increase in grades with all types of accommodations. Conversely, students with LD experienced a drop in grades with each accommodation.