This paper describes a comprehensive analysis of the effectiveness of four different education styles to study the enhancement of learning methods. The same instructional contents were taught by four different education styles. Their achievement scores were compared with education based on conventional lectures. The comparison result result shows that collaborative teaching using CAI(I)is the most effective among them. Compared with face-to-face lectures there is a difference at 1% level of significance either in the group with lower scores, in the group with higher scores, or in all. The effect of "human-to-computer interactions"advocated by cognitive science was shown quantitatively. It was also found that self-study at local offices using CAI(II)was effective in reducing the time required for learning by 24%. Based on the analytical results, the authors focused on self-study and developed self-study support functions on the www.