ci.pbcor: Confidence interval for a point-biserial correlation

In statpsych: Statistical Methods for Psychologists

Confidence interval for a point-biserial correlation

Description

Computes confidence intervals for two types of population point-biserial correlations. One type uses a weighted average of the group variances and is appropriate for nonexperimental designs with simple random sampling (rather than stratified random sampling). The other type uses an unweighted average of the group variances and is appropriate for experimental designs. Equality of variances is not assumed for either type.

Usage

ci.pbcor(alpha, m1, m2, sd1, sd2, n1, n2)

Arguments

alpha	alpha level for 1-alpha confidence
m1	estimated mean for group 1
m2	estimated mean for group 2
sd1	estimated standard deviation for group 1
sd2	estimated standard deviation for group 2
n1	sample size for group 1
n2	sample size for group 2

Value

Returns a 2-row matrix. The columns are:

• Estimate - estimated point-biserial correlation

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2020astatpsych

Examples

ci.pbcor(.05, 28.32, 21.48, 3.81, 3.09, 40, 40)

# Should return:
#              Estimate         SE        LL        UL
# Weighted:   0.7065799 0.04890959 0.5885458 0.7854471
# Unweighted: 0.7020871 0.05018596 0.5808366 0.7828948
 

statpsych documentation built on July 9, 2023, 6:50 p.m.