ci.pbcor: Confidence intervals for point-biserial correlations

In statpsych: Statistical Methods for Psychologists

Confidence intervals for point-biserial correlations

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 (but not 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.

For more details, see Section 1.18 of Bonett (2021, Volume 2)

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

\insertRef

Bonett2021statpsych

Examples

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

# Should return:
#             Estimate      SE     LL     UL
# Weighted:     0.7066 0.04891 0.5885 0.7854
# Unweighted:   0.7021 0.05019 0.5808 0.7829
 

statpsych documentation built on Jan. 13, 2026, 1:07 a.m.