DescTools (version 0.99.8.1)

KrippAlpha: 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")

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")