Sample Size to Select the Best Group in a Binomial Test

Computes the minimum sample size per group required to achieve a target probability of correctly selecting the best group in a binomial test. The best group is assumed to have success probability p1, and the other groups have p1 - dif.

Usage

ss_best_binomial(power, p1, dif, ngroups, max_n = 1000)

Arguments

power

Numeric. Desired probability of correctly selecting the best group (in [0, 1]).

p1

Numeric. Probability of success in the best group (in [0, 1]).

dif

Numeric. Difference in success probability with the next best group (> 0).

ngroups

Integer. Number of groups (must be > 1).

max_n

Integer. Maximum sample size to evaluate (default is 1000).

Value

An integer representing the minimum sample size per group required to reach the specified power.

Details

The function searches for the smallest npergroup such that the power from power_best_binomial is at least the target power.

Examples

ss_best_binomial(power = 0.9, p1 = 0.8, dif = 0.2, ngroups = 4)
#> [1] 33