(a).

	Coefficient of homogeneity	Cronbach's alpha
Extraversion scale E21	0.24	0.85
Extraversion subscale E9	0.39	0.80
Introversion I3	0.39	0.60

Coefficient of homogeneity.

0.30–0.39: just acceptable.

0.40–0.49: acceptable.

0.50 or higher: excellent.

Alpha: 0.80 or higher is excellent [1, 24].