The Impact of the PSP on Software Quality: Eliminating the Learning Effect Threat through a Controlled Experiment

Table 3

Descriptive statistics for the three variables under study.

	PSP0	PSP1	PSP2
Defect density in compile; (number of defects found in compile/KLOC)
Median	26.67	10.03	0.00
IQR	23.37	17.90	4.76
Mean	29.67	14.63	3.50
Defect density in unit testing; (number of defects found in UT/KLOC)
Median	18.76	9.93	5.41
IQR	16.29	15.22	14.03
Mean	20.60	12.94	8.04
Total defect density per KLOC; (number of defects found/KLOC)
Median	48.32	24.73	31.77
IQR	28.67	27.69	37.42
Mean	58.05	29.90	35.64