size.supinf.prop2 {statpsych} | R Documentation |
Computes the sample size in each group (assuming equal sample sizes) required to perform a superiority or inferiority test for the difference in population proportions with desired power in a 2-group design. For a superiority test, specify the upper limit (h) for the range of practical equivalence and specify values of p1 and p2 such that p1 - p2 > h. For an inferiority test, specify the lower limit (-h) for the range of practical equivalence and specify values of p1 and p2 such that p1 - p2 > -h. This function sets the effect size equal to p1 - p2.
size.supinf.prop2(alpha, pow, p1, p2, h)
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 |
lower or upper limit for range of practical equivalence |
Returns the required sample size per group
size.supinf.prop2(.05, .9, .35, .20, .05) # Should return: # Sample size per group # [1,] 408