size.ci.cronbach {statpsych} | R Documentation |
Computes the sample size required to estimate a Cronbach reliability with desired confidence interval precision.
size.ci.cronbach(alpha, rel, r, w)
alpha |
alpha value for 1-alpha confidence |
rel |
reliability planning value |
r |
number of measurements |
w |
desired confidence interval width |
Returns the required sample size
Bonett DG, Wright TA (2015). “Cronbach's alpha reliability: Interval estimation, hypothesis testing, and sample size planning.” Journal of Organizational Behavior, 36(1), 3–15. ISSN 08943796, doi: 10.1002/job.1960.
size.ci.cronbach(.05, .85, 5, .1) # Should return: # Sample size # [1,] 89