Cronbach's Alpha for Items or ScalesSource:
Compute various measures of internal consistencies for tests or item-scales of questionnaires.
The Cronbach's Alpha value for
x. A value closer to 1
indicates greater internal consistency, where usually following
rule of thumb is applied to interpret the results:
α < 0.5 is unacceptable,
0.5 < α < 0.6 is poor,
0.6 < α < 0.7 is questionable,
0.7 < α < 0.8 is acceptable,
and everything > 0.8 is good or excellent.
Bland, J. M., and Altman, D. G. Statistics notes: Cronbach's alpha. BMJ 1997;314:572. 10.1136/bmj.314.7080.572