kendall function

Kendall's coefficient of concordance W

Computes Kendall's coefficient of concordance as an index of interrater reliability of ordinal data. The coefficient could be corrected for ties within raters.

kendall(ratings, correct = FALSE)

Arguments

• ratings: n*m matrix or dataframe, n subjects m raters.
• correct: a logical indicating whether the coefficient should be corrected for ties within raters.

Details

Missing data are omitted in a listwise way.

Kendall's W should be corrected for ties if raters did not use a true ranking order for the subjects.

A test for the significance of Kendall's W is only valid for large samples.

Returns

A list with class '"irrlist"' containing the following components: - $method: a character string describing the method applied for the computation of interrater reliability.

• $subjects: the number of subjects examined.

• $raters: the number of raters.

• $irr.name: a character string specifying the name of the coefficient.

• $value: coefficient of interrater reliability.

• $stat.name: a character string specifying the name and the df of the corresponding chi-squared test.

• $statistic: the value of the test statistic.

• $p.value: the p-value for the test.

• $error: the character string of a warning message if ties were found within raters.

References

Kendall, M.G. (1948). Rank correlation methods. London: Griffin.

Author(s)

Matthias Gamer

See Also

cor, meanrho

Examples

data(anxiety)
kendall(anxiety, TRUE)