EVALUATING THE PREDICTIVE-VALIDITY OF MCAT SCORES ACROSS DIVERSE APPLICANT GROUPS

Purpose. To examine the predictive validity of MCAT scores, alone and in combination with other preadmission data, for medical students grou ped by race/ethnicity and sex. Method. This study included two samples : 1,109 students who entered in 1992 any of the 14 medical schools par ticipating in the MCAT predictive Validity Study; and all 11,219 stude nts who entered medical school in 1992 and took the USMLE Step 1 in lu ne 1994. Criterion measures included each student's cumulative GPA in the first two years of medical school and his or her pass/fail status on Step I. Differential predictive Validity was examined by comparing prediction errors across racial/ethnic and sex groups. For cumulative GPA, residuals were compared, and for Step 1, classification errors we re studied. Results. The patterns of prediction errors observed across the groups indicated that, on average, (1) no difference between the sexes in prediction errors was evident; (2) performances of the three racial/ethnic minority groups tended to be overpredicted, with signifi cant findings for Asians and Hispanics; and (3) Caucasians' performanc es tended to be underpredicted, although the magnitude of this underpr ediction was quite small. When USMLE Step 1 scores were the criterion for success in medical school, the majority of errors were overpredict ion errors. Conclusion. The authors caution that although MCAT scores, alone and in combination with undergraduate GPA, are good predictors of medical school performance, they are not perfect. The authors encou rage future research exploring additional predictor variables, such as diligence, motivation, communication skills, study habits, and other relevant characteristics. Similarly, they indicate that high grades an d Step I scores are not the only indicators of success in the medical profession and call for studies examining other important qualities, s uch as integrity interpersonal skills, capacity for caring, willingnes s to commit to lifelong learning, and desire to serve in underserved a reas.