Krippendorff's Alpha Reliability Coefficient
Calculate the alpha coefficient of reliability proposed by Krippendorff.
KrippAlpha(x, method=c("nominal", "ordinal", "interval", "ratio"))x |
classifier x object matrix of classifications or scores |
method |
data level of x |
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") |
Krippendorff's alpha coefficient is particularly useful where the level of measurement of classification data is higher than nominal or ordinal.
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.
Jim Lemon <jim@bitwrit.com.au>
Krippendorff, K. (1980) Content analysis: An introduction to its methodology. Beverly Hills, CA: Sage.
# 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")Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.