Kendall's u coefficient of agreement between judges.
Usage
kendall.u(M, cont.correct = FALSE)
Arguments
M
a square matrix or a data frame consisting of absolute choice
frequencies; row stimuli are chosen over column stimuli
cont.correct
logical, if TRUE a correction for continuity is
applied (by deducting 1 from chi2), default is FALSE
Value
uKendall's u coefficient of agreement
min.uthe minimum value for u
chi2the chi-square statistic for a test that the agreement is
by chance
dfthe degrees of freedom
pvalthe p-value of the test
Details
Kendall's u takes values between min.u (when agreement is minimum)
and 1 (when agreement is maximum).
The minimum min.u equals $-1/(m - 1)$, if $m$ is even,
and $-1/m$, if $m$ is odd, where $m$ is the number of subjects
(judges).
The null hypothesis in the chi-square test is that the agreement between
judges is by chance.
It is assumed that there is an equal number of observations per pair
and that each subject judges each pair only once.
References
Kendall, M.G., & Smith, B.B. (1940). On the method of paired comparisons.
Biometrika, 31, 324--345.