R: Krippendorff's Alpha Reliability Coefficient

KrippAlpha {DescTools} | R Documentation

## Krippendorff's Alpha Reliability Coefficient

### Description

Calculate the alpha coefficient of reliability proposed by Krippendorff.

### Usage

     KrippAlpha(x, method=c("nominal", "ordinal", "interval", "ratio"))

### Arguments

`x` | classifier x object matrix of classifications or scores
`method` | data level of x

### Value

A list with class '"irrlist"' containing the following components:

`method` | a character string describing the method.
`subjects` | the number of data objects.
`raters` | the number of raters.
`irr.name` | a character string specifying the name of the coefficient.
`value` | value of alpha.
`stat.name` | here "nil" as there is no test statistic.
`statistic` | the value of the test statistic (NULL).
`p.value` | the probability of the test statistic (NULL).
`cm` | the concordance/discordance matrix used in the calculation of alpha
`data.values` | a character vector of the unique data values
`levx` | the unique values of the ratings
`nmatchval` | the count of matches, used in calculation
`data.level` | the data level of the ratings ("nominal","ordinal", "interval","ratio")

### Note

Krippendorff's alpha coefficient is particularly useful where the level of measurement of classification data is higher than nominal or ordinal.

### Note

This function was previously published as `kripp.alpha()` in the irr package and has been integrated here without logical changes, but with some adaptations in the result structure.

### Author(s)

Jim Lemon <jim@bitwrit.com.au>

### References

Krippendorff, K. (1980) Content analysis: An introduction to its methodology. Beverly Hills, CA: Sage.

### Examples

    # the "C" data from Krippendorff
     nmm <- matrix(c(1,1,NA,1,2,2,3,2,3,3,3,3,3,3,3,3,2,2,2,2,1,2,3,4,4,4,4,4,
                     1,1,2,1,2,2,2,2,NA,5,5,5,NA,NA,1,1,NA,NA,3,NA), nrow=4)

     # first assume the default nominal classification
     KrippAlpha(nmm)

     # now use the same data with the other three methods
     KrippAlpha(nmm, "ordinal")
     KrippAlpha(nmm, "interval")
     KrippAlpha(nmm, "ratio")

[Package DescTools version 0.99.35 Index]