**Hey dear R-Community,**

***I want to use my data sample, to calculate the intra-class-correlation of the three raters. ***

**My colleague sent the following syntax with which she calculated it for a different sample.**

Ttemp1 <- read.xlsx2("coding_format.xlsx",1,colIndex=c(1:21),colClasses=c("numeric","numeric","character",rep("numeric",16),"character","character"))

```
T.temp1 <- read.xlsx2("coding_format_draft c_Trier_Study_1.xlsx",1,colIndex=c(1:21),colClasses=c("numeric","numeric","character",rep("numeric",16),"character","character"))
T.temp1 <- T.temp1[order(T.temp1$id,T.temp1$session,T.temp1$rater_EXP,T.temp1$Segment),]
```

```
IDs<-unique(T.temp1$id)
```

```
T.temp2<-data.frame(matrix(nrow = 0,ncol = 37))
names<-names(T.temp1)[-3]
names2<-names[4:20]
names3<-paste("b",names2,sep="_")
```

```
names4<-c(names,names3)
names(T.temp2)<-names4
```

```
for (t in IDs){
#t<-IDs[1]
temp1<-subset(T.temp1,id==t)
Sessions<-unique(temp1$session)
for (s in Sessions){
#s<-Sessions[1]
temp2<-subset(temp1,session==s)
coders<-unique(temp2$rater_EXP)
if (length(coders)==1){
temp3<-subset(temp2,select = -rater_EXP)
temp3<-data.frame(temp3,matrix(ncol=17))
names(temp3)<-names4
} else{
temp3.1<-subset(temp2,rater_EXP==coders[1], select = -rater_EXP)
temp3.2<-subset(temp2,rater_EXP==coders[2], select = -rater_EXP)
names<-names(temp3.2)[4:20]
for (i in names){
names(temp3.2)[names(temp3.2)==i]<-paste("b",i,sep="_")
}
temp3<-merge(temp3.1,temp3.2, by=c("id","session","Segment"),all = T,sort=T)
length(temp3[1,])
}
T.temp2<-rbind(T.temp2,temp3)
}
}
```

**Since im very new to R, i cant really follow the steps she has made preparing the data. Can someone please explain the steps/or part of the steps she made linking it to the syntax so that I'm able to apply it to my data set.**

The calculation of the ICC itself and the syntax that belongs to it is rather easy to understand.

```
T.temp2 <- T.temp2[order(T.temp2$id,T.temp2$session,T.temp2$Segment),]
#write.table(T.temp2,file="clipboard-12000",sep="\t",col.name=NA)
#summary(T.temp2)
#ICC for mode and peak
library(psych)
mode<-T.temp2[,c(4,21)]
mode<-mode[complete.cases(mode),]
mode.icc<-ICC(mode)
mode.icc
#write.table(mode,file="clipboard-12000",sep="\t",col.name=NA)
peak<-T.temp2[,c(5,22)]
peak<-peak[complete.cases(peak),]
peak.icc<-ICC(peak)
peak.icc
```