Predictive Validity of Accommodated LSAT Scores (TR-01-01)
Andrea E. Thornton, Lynda M. Reese, Peter J. Pashley, and Susan P. Dalessandro

Executive Summary

This study was undertaken to evaluate the predictive validity of Law School Admission Test (LSAT) scores earned under accommodated testing conditions. Of special interest was the validity of scores obtained by test takers who were accommodated under nonstandard time conditions (i.e., accommodations that included extra testing time). Within this group, separate predictive validity analyses were also conducted for those test takers who were classified within Attention Deficit/Hyperactivity Disorder (ADHD), Learning Disability (LD), Neurological Impairment, and Visual Impairment subgroups. Of secondary interest was the validity of LSAT scores obtained by test takers who were accommodated under standard time conditions (i.e., accommodations that did not include extra testing time).

The measure used to assess the predictive validity of the LSAT for the above groups was law school first-year average (FYA). The predictive validity of undergraduate grade-point average (UGPA) was also evaluated, as was the combination of LSAT score and UGPA, commonly referred to as the Index. The sample used in this study was drawn from 590 entering law school classes from 168 individual law schools collected over five years.

The results from this study strongly suggest that:

  • LSAT scores earned under accommodated testing conditions that included extra testing time are not comparable to LSAT scores earned under standard timing conditions as evidenced by a tendency of the former to overpredict FYAs (i.e., estimated FYAs based on scores from test takers accommodated with extra testing time tend to be higher than their actual FYAs); and 

  • results for test takers categorized within the ADHD, LD, Neurological Impairment, and Visual Impairment subgroups; and within the accommodated with extra testing time sample, were consistent with the overall group finding stated above.

These findings are consistent with those found previously by Wightman in her research report 93-03 published by LSAC. This current study also indicates that:

  • LSAT scores earned under standard timing conditions are comparable, regardless of whether or not other (nontiming related) accommodations are given.

The results from this study indicate that LSAT scores obtained under accommodated conditions that included extra testing time should be evaluated with care. However, more data and further analyses will be required before more specific statements can be made, such as whether UGPA is a better predictor of FYA than LSAT scores for test takers accommodated with extra testing time.


Predictive Validity of Accommodated LSAT Scores (TR-01-01)

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