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. https://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-016-0200-9

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.

See Also

CronbachAlpha, KappaM, CohenKappa

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") 

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