As shown in Figure 1&2, the distribution of students’ total scores in pre-test and post-test was slightly different.
Before taking the course, the distribution of total scores was skewed to the left. Only several were found to fall
on the higher score range of the scale. After the taking the course, the distribution of total scores showed a
double-peaking. While some students moved to the higher score range, the others still stayed at lower score
range.