Thornton, A. E., Reese, L. M., Pashley, P. J., & Dalessandro, S. P. (2002). Predictive validity of accommodated LSAT scores . Law School Admission Council. http://files.eric.ed.gov/fulltext/ED469183.pdf

Technical Report LSAC Research Report Series

The validity of scores obtained by test takers who were administered the test under nonstandard time conditions (i.e., accommodations that included extended-time) was investigated.

The total of 1,458 students with disabilities was compared with the 121,607 students without disabilities who were commencing law school courses at 168 law schools throughout the U.S. over 5 years, totaling 590 cohorts of students. Approximately 1,249 students with disabilities received accommodations, and 209 students with disabilities did not. Separate predictive validity analyses were conducted for test takers with various categories of disabilities, including attention-deficit hyperactivity disorder (ADHD), learning disabilities, neurological impairments, and visual impairments. Students with disabilities completing the LSAT totaled 1,458 students with disabilities overall.

The measure used to assess the predictive validity of the Law School Admissions Test (LSAT) for participant groups was law school first year average grades.

Overall, LSAT scores earned under the nonstandard time condition were not comparable to LSAT scores earned under standard timing conditions. Results for individual subgroups were consistent with the overall group result.