This study was designed and conducted to determine the effectiveness of audio-tutorial minicourses in increasing achievement in the biological sciences at the college freshman level. In 1971, 75 randomly selected students in the experimental group attended regular lecture and laboratory periods in addition to completing 10 minicourses. The 79 students in the control group also attended regular lecture and laboratory periods but completed library assignments on topics covered in the minicourses. Pretests and posttests were administered to both groups after completing a topic. Data were based on the Otis Self-Administering Test of Mental Ability: Form A, and a general biology pretest and posttest. The findings indicate that audio-tutorial minicourses used as an adjunct to lecture and laboratory techniques did assist students in learning as indicated on student evaluations. However, the study found no significant difference to exist between the posttest means of audio-tutorial group and the library research groups when the data were treated by analysis of covariance. (Author/BR)