Sample size for a test of a paired-samples mean difference

Computes the sample size required to test a difference in population means with desired power in a paired-samples design. Set the Pearson correlation planning value to the smallest value within a plausible range, and set the variance planning value to the largest value within a plausible range for a conservatively large sample size.

Usage

size.test.mean.ps(alpha, pow, var, es, cor)

Arguments

alpha: alpha level for hypothesis test
pow: desired power
var: planning value of average variance of the two measurements
es: planning value of mean difference
cor: planning value of correlation

Value

Returns the required sample size

Examples

size.test.mean.ps(.05, .80, 1.25, .5, .75) 
#>  Sample size
#>           22

# Should return:
# Sample size
#          22