Computes the sample size required to estimate a Cronbach reliability with desired confidence interval precision.

size.ci.cronbach(alpha, rel, r, w)

Arguments

alpha

alpha value for 1-alpha confidence

rel

reliability planning value

r

number of measurements

w

desired confidence interval width

Value

Returns the required sample size

References

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 .

Examples

size.ci.cronbach(.05, .85, 5, .1)
#>      Sample size
#> [1,]          89

# Should return:
#      Sample size
# [1,]          89