Computes the sample size required to perform an equivalence test for the difference in population means with desired power in a paired-samples design. The value of h specifies a range of practical equivalence, -h to h, for the difference in population means. The planning value for the absolute mean difference must be less than h. Equivalence tests often require a very large sample size. Equivalence tests usually use 2 x alpha rather than alpha (e.g., use alpha = .10 rather alpha = .05). Set the Pearson correlation 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.
size.equiv.mean.ps(alpha, pow, var, es, cor, h)alpha level for hypothesis test
desired power
planning value of average variance of the two measurements
planning value of mean difference
planning value of the correlation between measurements
upper limit for range of practical equivalence
Returns the required sample size
size.equiv.mean.ps(.10, .85, 15, .5, .7, 1.5)
#> Sample size
#> 68
# Should return:
# Sample size
# 68