kap {epicalc}R Documentation

Kappa statistic

Description

Measurement of agreement in categorization

Usage

kap(kaptable, wttable = NULL) 

Arguments

kaptable Cross tabulation of classifications made by two raters
wttable Cross tabulation of weights of agreement among categories

Details

'kap' computes the kappa statistic, the level of agreement between two raters.

Author(s)

Virasakdi Chongsuvivatwong <cvirasak@medicine.psu.ac.th>

See Also

'table'

Examples

class  <- c("Normal","Benign","Suspect","Cancer")
raterA <- gl(4,4, label=class)
raterB <- gl(4,1,16, label=class)
freq   <- c(50,2,0,1,2,30,4,3,0,0,20,1,1,3,4,25)
table1 <- xtabs(freq ~ raterA + raterB)
table1
kap(table1)
wt <-c(1,.5,0,0,.5,1,0,0,0,0,1,.8,0,0,.8,1)
wttable <- xtabs(wt ~ raterA + raterB)
wttable # Agreement between benign vs normal is .5, suspect vs cancer is .8
kap(table1, wttable=wttable)

[Package epicalc version 2.4.0.11 Index]