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

Table 7

Descriptive statistics for the three variables under study.

	Progs1-2	Progs3-4	Progs5–8
Defect density in compile; (number of defects found in Compile/KLOC)
Median	56.58	39.72	37.83
IQR	75.48	45.32	39.15
Mean	78.21	59.08	44.12
Defect density in unit testing; (number of defects found in UT/KLOC)
Median	39.10	16.45	19.82
IQR	17.58	20.01	18.30
Mean	54.57	20.13	27.38
Total defect density per KLOC; (number of defects found/KLOC)
Median	114.40	64.33	66.50
IQR	82.13	51.87	48.87
Mean	134.91	79.96	72.07