Scores on the four subtests of the old Medical College Admission Test (MCAT) and the six subtests of the new edition (1978) were factor analyzed. Scores were derived from similar groups of applicants. Two-factors, verbal-general information and science-quantitative, known from previous factorial studies of the old MCAT, emerged again. Five of the six subtests of the new edition load on the science-quantitative factor. Problem solving skill is not clearly differentiated from knowledge in the three science areas. Only the reading subtest loads on the verbal-general information factor so clearly assessed in the old MCAT. Most admissions committees interpret the new MCAT either by averaging all six subtests, or by determining if any subtest score falls below a preset level. The science-quantitative factor may thus inadvertently be given twice the weight of the verbal ability factor. Instead, two scores should be calculated: the mean of the four science subtests, and the mean of the two skills analysis subtests. Each candidate would then be represented by two scores, not six or one. (Author/CP)