size.ci.rsqr {statpsych}

Sample size for a squared multiple correlation confidence interval

Description

Computes the sample size required to estimate a population 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.

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, .25, 5, .2)

# Should return:
# Sample size
#         214