ci.lc.prop.bs: Confidence interval for a linear contrast of proportions in a...

In statpsych: Statistical Methods for Psychologists

Confidence interval for a linear contrast of proportions in a between- subjects design

Description

Computes an adjusted Wald confidence interval for a linear contrast of population proportions in a between-subjects design.

For more details, see Section 2.8 of Bonett (2021, Volume 3)

Usage

ci.lc.prop.bs(alpha, f, n, v)

Arguments

alpha	alpha level for 1-alpha confidence
f	vector of frequency counts of participants who have the attribute
n	vector of sample sizes
v	vector of between-subjects contrast coefficients

Value

Returns a 1-row matrix. The columns are:

• Estimate - adjusted estimate of proportion linear contrast

• SE - adjusted standard error

• z - z test statistic

• p - two-sided p-value

• LL - lower limit of the adjusted Wald confidence interval

• UL - upper limit of the adjusted Wald confidence interval

References

\insertRef

Price2004statpsych

\insertRef

Bonett2021statpsych

Examples

f <- c(26, 24, 38)
n <- c(60, 60, 60)
v1 <- c(-.5, -.5, 1)
ci.lc.prop.bs(.05/2, f, n, v1)

# Should return:
#  Estimate         SE      z       p        LL        UL
# 0.2119565 0.07602892 2.7878 0.00531 0.0415451 0.3823679

v2 <- c(1, -1, 0)
ci.lc.prop.bs(.05/2, f, n, v2)

# Should return:
#   Estimate         SE       z       p         LL        UL
# 0.03225806 0.08857951 0.36417 0.71573 -0.1662843 0.2308004

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