size.ci.lc.stdmean.bs: Sample size for a between-subjects standardized linear...

In statpsych: Statistical Methods for Psychologists

Sample size for a between-subjects standardized linear contrast of means confidence interval

Description

Computes the sample size per group (assuming equal sample sizes) required to estimate two types of standardized linear contrasts of population means (unweighted average standardizer and single group standardizer) with desired confidence interval precision in a between-subjects design. Set the standardized linear contrast of means to the largest value within a plausible range for a conservatively large sample size.

Usage

size.ci.lc.stdmean.bs(alpha, d, w, v)

Arguments

alpha	alpha level for 1-alpha confidence
d	planning value of standardized linear contrast of means
w	desired confidence interval width
v	vector of between-subjects contrast coefficients

Value

Returns the required sample size per group for each standardizer

References

\insertRef

Bonett2009statpsych

Examples

v <- c(.5, .5, -.5, -.5)
size.ci.lc.stdmean.bs(.05, 1, .6, v)

# Should return:
#                            Sample size per group
# Unweighted standardizer:                      49
# Single group standardizer:                    65
 

statpsych documentation built on Sept. 11, 2024, 7:42 p.m.