size.interval.cor {statpsych}

Sample size for an interval test of a Pearson or partial correlation

Description

Computes the sample size required to perform an interval test for a population Pearson or a partial correlation with desired power where the interval midpoint is equal to zero. This function can be used to plan a study where the goal is to show that the population correlation is small. Set s = 0 for a Pearson correlation. The correlation planning value must be a value within the hypothesized interval.

Usage

size.interval.cor(alpha, pow, cor, s, h)

Arguments

alpha

alpha level for hypothesis test

pow

desired power

cor

planning value of correlation

s

number of control variables

h

upper limit of hypothesized interval

Value

Returns the required sample size

Examples

size.interval.cor(.05, .8, .1, 0, .25)

# Should return:
# Sample size
#         360