ci.lc.median.bs: Confidence interval for a linear contrast of medians in a...

In statpsych: Statistical Methods for Psychologists

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

Description

Computes a distribution-free confidence interval for a linear contrast of medians in a between-subjects design using estimated medians and their standard errors. The sample median and standard error for each group can be computed using the ci.median) function.

Usage

ci.lc.median.bs(alpha, m, se, v)

Arguments

alpha	alpha level for 1-alpha confidence
m	vector of estimated group medians
se	vector of group standard errors
v	vector of between-subjects contrast coefficients

Value

Returns a 1-row matrix. The columns are:

• Estimate - estimated linear contrast of medians

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2002statpsych

Examples

m <- c(46.13, 29.19, 30.32, 49.15)
se <- c(6.361, 5.892, 4.887, 6.103)
v <- c(1, -1, -1, 1)
ci.lc.median.bs(.05, m, se, v)

# Should return:
# Estimate       SE       LL       UL
#    35.77 11.67507 12.88727 58.65273

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