The Validity of Law School Admission Test Scores for Repeat Test Takers: 2005 Through 2008 Entering Law School Classes (TR 10-02)
by Andrea Thornton Sweeney, Laura A. Marcus, and Lynda M. Reese
Executive Summary
When faced with multiple scores from repeat test takers, users of standardized
assessments typically employ three indices—most recent, highest, and average
scores—in order to summarize an individual's related performance. This study
examines the validity of these three indices for Law School Admission Test (LSAT)
scores in terms of predicting first-year averages (FYAs). A fourth index—the initial
score—was also considered in order to provide additional baseline information.
Confirming earlier research study results, this study found that, among the indices
considered, the simple arithmetic average of multiple scores provided the best
prediction of subsequent law school performance for repeat test takers. This finding
held when LSAT scores were considered alone or in combination with undergraduate
grade point averages (UGPAs).
Note that this and previous studies also underscore the need to consider individual
circumstances when evaluating scores for repeat test takers. That is, score users
should evaluate multiple scores in the context of any additional valid documentation that
might be available suggesting that any of an applicant's test scores may not accurately
reflect his or her actual abilities.
The current study was based on data from US ABA-approved law schools that
participated in the 2008 and 2009 LSAT Correlation Studies. Results for four entering
classes, from the fall of 2005 through the fall of 2008, were combined within each
school. The sample contains only the 184 schools whose combined enrollment included
a total of 50 or more first-year students who had taken the LSAT on more than one
occasion. Data were combined across 4 years, as available, in order to obtain sample
sizes large enough to ensure stability in the validity estimates. In addition to validity
results, this study provides descriptive summaries comparing one-time test takers with
repeat test takers. Repeat test takers tend to earn lower LSAT scores than one-time test
takers regardless of whether the most recent, initial, highest, or average score is
considered. One-time test takers also tend to have slightly higher UGPAs and FYAs.