ci.ratio.median2: Confidence interval for a 2-group median ratio

In statpsych: Statistical Methods for Psychologists

Confidence interval for a 2-group median ratio

Description

Computes a distribution-free confidence interval for a ratio of population medians of ratio-scale measurements in a 2-group design. Tied scores within each group are assumed to be rare.

For more details, see Section 2.12 of Bonett (2021, Volume 1)

Usage

ci.ratio.median2(alpha, y1, y2)

Arguments

alpha	alpha level for 1-alpha confidence
y1	vector of scores for group 1
y2	vector of scores for group 2

Value

Returns a 1-row matrix. The columns are:

• Median1 - estimated median for group 1

• Median2 - estimated median for group 2

• Median1/Median2 - estimated ratio of medians

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2020bstatpsych

\insertRef

Bonett2021statpsych

Examples

y2 <- c(32, 39, 26, 35, 43, 27, 40, 37, 34, 29, 49, 42, 40)
y1 <- c(36, 44, 47, 42, 49, 39, 46, 31, 33, 48)
ci.ratio.median2(.05, y1, y2)

# Should return:
# Median1 Median2 Median1/Median2       LL       UL
#      43      37        1.162162 0.927667 1.455933

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