Three key PSP measures, i.e . time in design phase, size of added and modified codes and overall defects, were collected from the students. Fig. 3 display average values of these data Yet, due to the fact that each assignment represents different level of difficulty, these values need further refinement Two new metrics were calculated in order to further analyze the data. Firstly, time in design phase per one thousand added and modified codes (Time Design/KLOC) designated the ratio of all time used in the designing phase based on the amount of source code created in the program. Secondly, overall defects per one thousand added and modified codes (Defects/KLOC) displayed information of defect density. ANOVA were used for comparing and finding significance between means of these two groups of data. The significance is set at α = 0.05. Figure 4 display the value of both new metrics.