Computes the sample size in each group (assuming equal sample sizes) required to perform an equivalence test for the difference in population proportions with desired power in a 2-group design. The value of h specifies a range of practical equivalence, -h to h, for the difference in population proportions. The absolute difference in the proportion planning values 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 than alpha = .05).

size.equiv.prop2(alpha, pow, p1, p2, h)

Arguments

alpha

alpha level for hypothesis test

pow

desired power

p1

planning value of proportion for group 1

p2

planning value of proportion for group 2

h

upper limit for range of practical equivalence

Value

Returns the required sample size per group

Examples

size.equiv.prop2(.1, .8, .30, .35, .15)
#>      Sample size
#> [1,]         288

# Should return:
#      Sample size per group
# [1,]                   288