pwr.2p.test: Power calculation for two proportions (same sample sizes)

Description

Compute power of test, or determine parameters to obtain target
power (similar to power.prop.test).

Usage

pwr.2p.test(h = NULL, n = NULL, sig.level = 0.05, power = NULL,
alternative = c("two.sided","less","greater"))

Arguments

h

Effect size

n

Number of observations (per sample)

sig.level

Significance level (Type I error probability)

power

Power of test (1 minus Type II error probability)

alternative

a character string specifying the alternative hypothesis,
must be one of "two.sided" (default), "greater" or
"less"

Value

Object of class '"power.htest"', a list of the arguments
(including the computed one) augmented with 'method' and 'note'
elements.

Details

Exactly one of the parameters 'h','n', 'power' and
'sig.level' must be passed as NULL, and that parameter is
determined from the others. Notice that the last one has non-NULL
default so NULL must be explicitly passed if you want to compute
it.

References

Cohen, J. (1988). Statistical power analysis for the
behavioral sciences (2nd ed.). Hillsdale,NJ: Lawrence Erlbaum.