The Validity of Law School Admission Test Scores for Repeat Test Takers: 2010 Through 2014 Fall-Entering Law School Classes (TR 18-02)
When faced with multiple scores from repeat test takers, users of standardized assessments typically employ three score types — most recent, highest, and average scores — in order to summarize an individual’s related performance. This study examined the validity of these three score types for Law School Admission Test (LSAT) scores in terms of predicting first-year averages (FYAs), taking into account differential validity and differential prediction between one-time and repeat test takers. To provide additional baseline information, a fourth score type — the initial score — was also considered. Confirming earlier research study results, the current study found that among the score types considered, the simple arithmetic average of multiple scores displayed the strongest relationship to FYA and provided the best prediction of subsequent law school performance for repeat test takers. These findings held when LSAT scores were considered alone or in combination with undergraduate grade point averages (UGPAs).
The current study was based on data from U.S. ABA-approved law schools that participated in the 2011–2015 LSAT Correlation Studies. Results for five fall-entering classes, from 2010 through 2014, were combined within each school. The sample contains only the 183 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 5 years, as available, in order to obtain sample sizes large enough to ensure stability in the validity coefficients. In addition to validity results, this study provides descriptive summaries comparing one-time test takers with repeat test takers. On average, 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, on average.
Note that this and previous studies 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 could indicate instances where an applicant’s test scores may not accurately reflect his or her actual abilities.