 After field testing a preliminary version of the Aptitude Battery on secondary school students of French and Spanish, Pimsleur and his associates identified verbal intelligence, motivation and auditory ability as the three most significant factors in predicting success at learning a foreign language.They developed seven subtests that would measure these three factors.After testing the seven subtests, with the support of the Ohio State University Research Foundation, the PLAB was finalized by adding a part where the examinee indicates his or her grade point average in four core subjects.