Modified RESALI version
parent
a2fec9c87d
commit
13d80a3e74
Binary file not shown.
@ -0,0 +1,78 @@
|
||||
library(TAM)
|
||||
|
||||
resali <- function(df=NULL,items=NULL,group=NULL,verbose=T) {
|
||||
if (verbose) {
|
||||
cat('-----------------------------------------------------------\n')
|
||||
cat('COMPUTING INITIAL PCM\n')
|
||||
cat('-----------------------------------------------------------\n')
|
||||
}
|
||||
nbitems <- length(items)
|
||||
nbitems_o <- nbitems
|
||||
items_n <- paste0('item',items)
|
||||
resp <- df[,items_n]
|
||||
grp <- df[,group]
|
||||
pcm_initial <- TAM::tam.mml(resp=resp,Y=grp,irtmodel = "PCM",est.variance = T,verbose=F)
|
||||
dat <- df
|
||||
dat$score <- rowSums(dat[,items_n])
|
||||
dat$score_q5 <- cut(dat$score,quantile(dat$score,seq(0,1,0.2)),labels=1:5,include.lowest=T)
|
||||
res.anova <- rep(NA,nbitems)
|
||||
pval <- rep(NA,nbitems)
|
||||
fval <- rep(NA,nbitems)
|
||||
for (i in items) {
|
||||
dat[,paste0('res_',i)] <- rowMeans(predict(pcm_initial)$stand.resid[,,i])
|
||||
res.anova[i] <- summary(aov(dat[,paste0('res_',i)]~TT*score_q5,data=dat))
|
||||
pval[i] <- res.anova[[i]][1,"Pr(>F)"]
|
||||
fval[i] <- res.anova[[i]][1,'F value']
|
||||
}
|
||||
if (verbose) {
|
||||
cat('DONE\n')
|
||||
cat('-----------------------------------------------------------\n')
|
||||
}
|
||||
res.items <- c()
|
||||
res.uniform <- c()
|
||||
k <- 1
|
||||
while(any(pval<0.05/nbitems_o)) {
|
||||
k <- k+1
|
||||
if (verbose) {
|
||||
cat(paste('COMPUTING STEP',k,'\n'))
|
||||
cat('-----------------------------------------------------------\n')
|
||||
}
|
||||
res.item <- gsub("[a-z]", "",colnames(resp)[which.max(fval)])
|
||||
res.items <- c(res.items,res.item)
|
||||
res.uni <- res.anova[[which.max(fval)]][3,"Pr(>F)"]>0.05
|
||||
res.uniform <- c(res.uniform,res.uni)
|
||||
items_n <- c(items_n[items_n!=paste0('item',res.item)],paste0("item",res.item,c("noTT","TT")))
|
||||
dat[,paste0("item",res.item,'TT')] <- dat[dat$TT==1,paste0('item',res.item)]
|
||||
dat[,paste0("item",res.item,'noTT')] <- dat[dat$TT==0,paste0('item',res.item)]
|
||||
resp <- dat[,items_n]
|
||||
grp <- dat[,group]
|
||||
pcm_while <- TAM::tam.mml(resp=resp,Y=grp,irtmodel = "PCM",est.variance = T,verbose=F)
|
||||
nbitems <- length(items_n)
|
||||
res.anova <- rep(NA,nbitems)
|
||||
pval <- rep(NA,nbitems)
|
||||
fval <- rep(NA,nbitems)
|
||||
for (i in 1:nbitems) {
|
||||
dat[,paste0('res_',i)] <- rowMeans(predict(pcm_while)$stand.resid[,,i])
|
||||
res.anova[i] <- summary(aov(dat[,paste0('res_',i)]~TT*score_q5,data=dat))
|
||||
pval[i] <- res.anova[[i]][1,"Pr(>F)"]
|
||||
fval[i] <- res.anova[[i]][1,'F value']
|
||||
}
|
||||
if (verbose) {
|
||||
cat('DONE\n')
|
||||
cat('-----------------------------------------------------------\n')
|
||||
}
|
||||
}
|
||||
if (verbose) {
|
||||
cat("DETECTED DIF ITEMS\n")
|
||||
cat('-----------------------------------------------------------\n')
|
||||
}
|
||||
if (length(res.items>0)) {
|
||||
results <- data.frame(dif.items=res.items,
|
||||
uniform=1*res.uniform)
|
||||
return(results)
|
||||
}
|
||||
else {
|
||||
cat("No DIF was detected")
|
||||
return(NULL)
|
||||
}
|
||||
}
|
Loading…
Reference in New Issue