Eleven tutorial-drill and four experiment-simulation computer assisted instruction (CAI) modules were designed and programmed for use on an IBM 1500 system. The modules were designed as supplementary study aids for an introductory chemistry course and were intended to assist students' achievement of specified behavioral objectives. After trial testing and revision, the modules were evaluated by comparing groups having access to the programs and a control group on the basis of attainment of the behavioral objectives and performance on the final examination. Data showed that the CAI programs aided the acquisition of the behavioral objectives and had a significant effect on the final examination score. Some confounding factors of test reliability and validity limit generalization of the data. (Author/AL)