size.ci.rsqr {statpsych}R Documentation

Sample size for a squared multiple correlation confidence interval

Description

Computes the sample size required to estimate a squared multiple correlation in a random-x regression model with desired confidence interval precision. Set the planning value of the squared multiple correlation to 1/3 for a conservatively large sample size. This function uses an approximation to the standard error of the squared multiple correlation.

Usage

size.ci.rsqr(alpha, r2, s, w)

Arguments

alpha

alpha level for 1-alpha confidence

r2

planning value of squared multiple correlation

s

number of predictor variables in model

w

desired confidence interval width

Value

Returns the required sample size

Examples

size.ci.rsqr(.05, .333, 2, .2)

# Should return:
#      Sample size
# [1,]         232
 


[Package statpsych version 1.3.0 Index]