size.ci.pbcor: Sample size for a point-biserial correlation confidence...

In statpsych: Statistical Methods for Psychologists

Sample size for a point-biserial correlation confidence interval

Description

Computes the sample size required to estimate a population point-biserial correlation with desired confidence interval precision in a two-group nonexperimental design with simple random sampling. A two-group nonexperimental design implies two subpopulations (e.g., all boys and all girls in a school district). This function requires a planning value for the proportion of population members who belong to one of the two subpopulations. Set the correlation planning value to the smallest absolute value within a plausible range for a conservatively large sample size.

Usage

size.ci.pbcor(alpha, cor, w, p)

Arguments

alpha	alpha level for 1-alpha confidence
cor	planning value of point-biserial correlation
w	desired confidence interval width
p	proportion of members in one of the two subpopulations

Value

Returns the required sample size

References

\insertRef

Bonett2020astatpsych

Examples

size.ci.pbcor(.05, .40, .25, .73)

# Should return:
# Sample size
#         168
 

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