<?xml version="1.0" encoding="utf-8"?><!DOCTYPE article  PUBLIC '-//OASIS//DTD DocBook XML V4.4//EN'  'http://www.docbook.org/xml/4.4/docbookx.dtd'><article><articleinfo><title>FAQ/BPkapCIR</title><revhistory><revision><revnumber>5</revnumber><date>2013-03-08 10:17:28</date><authorinitials>localhost</authorinitials><revremark>converted to 1.6 markup</revremark></revision><revision><revnumber>4</revnumber><date>2012-08-08 10:56:12</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>3</revnumber><date>2012-08-08 10:55:25</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>2</revnumber><date>2012-08-08 10:54:24</date><authorinitials>PeterWatson</authorinitials></revision><revision><revnumber>1</revnumber><date>2012-08-08 10:52:59</date><authorinitials>PeterWatson</authorinitials></revision></revhistory></articleinfo><section><title>95% Bootstrap confidence intervals for Brennan and Prediger (1981) kappa</title><para>The complete case data is in this SPSS <ulink url="https://lsr-wiki-01.mrc-cbu.cam.ac.uk/statswiki/FAQ/BPkapCIR/statswiki/FAQ/BPkapCIR?action=AttachFile&amp;do=get&amp;target=raters.sav">file</ulink>. The directory name may need to be changed in the read.spss command argument to identify the location on your PC of your data file. </para><screen><![CDATA[library(foreign)
x <- read.spss("U://My Documents//raters.sav")
x1 <- data.frame(x)
attach(x1)
]]><![CDATA[
]]><![CDATA[
# Evaluates a bootstrap 95% CI for Brennan and Prediger's (1981) kappa for random numbers of categories to rate (for two raters)
# Ratings are in  SPSS file in two columns called rater1 and rater2
#
 
#
nb<-1000
n <- length(rater1)
boot<-matrix(NA,nb,n)
boot1<-matrix(NA,nb,n)
bsum <- matrix(NA,nb,1)
kapbp <- matrix(NA,nb,1)
]]><![CDATA[
attributes(boot)
for (i in 1:nb) {
bs1<-sample(rater1,n,replace=T)
bs2<-sample(rater2,n,replace=T)
for (j in 1:n) {
boot[i,j] <- bs1[j]-bs2[j]
boot1[i,j] <- ifelse(boot[i,j] == 0,1,0)
}
kapbp[i] <-  ( (sum(boot1[i,])/n) - (1/n))/(1 - (1/n)) 
}
]]><![CDATA[
hist(kapbp)
quantile(kapbp,0.025)
quantile(kapbp,0.975)]]></screen></section></article>