multiEquatError | R Documentation |
Function computes linking errors based on the 1pl linking procedure according
to equating.rasch
from the sirt
package for three measurement
occasions.
multiEquatError (x1, x2, x3, difBound = 1, dependentDIF =FALSE, testletStr = NULL, verbose = TRUE )
x1 |
The object returned by |
x2 |
The object returned by |
x3 |
The object returned by |
difBound |
Defines the boundary. Items with absolute linking DIF greater than the boundary will be removed from the linking procedure. |
dependentDIF |
Logical. If DIF is assumed to be correlated between measurement occasions one and two versus two and three, this covariance will be taken into account. If the assumption of linear dependency does not seem reasonable, this option possibly results in overfitting and underestimation of the true linking error. |
testletStr |
Optional: A data.frame with two columns. First column: testlet identifier, should be named |
verbose |
Logical: print linking informations to console? |
description needed
Karoline Sachse, with code borrowed from the sirt package
Monseur, C., & Berezner, A. (2007). The Computation of Equating Errors in International Surveys in Education. Journal of Applied Measurement 8(3): 323-335.
data(trends)
################################################################################
### Example 1: Linking for three measurement occasions and one domain ###
################################################################################
# calibrate all three measurements, using a unidimensional model each (only reading)
results <- by(data = trends, INDICES = trends[,"year"], FUN = function (y){
dat <- reshape2::dcast(subset ( y, domain == "reading"), idstud~item, value.var="value")
def <- defineModel(dat=dat, items= -1, id="idstud", software="tam")
run <- runModel(def)
res <- getResults(run)
return(res)})
lErrors <- multiEquatError(results[[1]], results[[2]], results[[3]], difBound = 0.64)
# dependent DIF
lErrDif <- multiEquatError(results[[1]], results[[2]], results[[3]], difBound = 0.64, dependentDIF =TRUE)
# Following code demonstrates the replacement of old linking error in the 'equatingList' object
# for further processing
# direct linking 1 to 3 (1 is reference)
it1 <- itemFromRes(results[[1]])
eq1.vs.3<- equat1pl(results[[3]], prmNorm = it1[,c("item", "est")], difBound = 0.64, iterativ = TRUE)
# replace 'direct' linking error with 'indirect' linking error from 'multiEquatError()'
eq1.vs.3<- replaceLinkingError (equatingList=eq1.vs.3, multiEquatError_output=lErrors)
################################################################################
### Example 2: Linking for three measurement occasions and two domains ###
################################################################################
# calibrate all three measurements, using a unidimensional model each
# reading and listening are handled subsequently, using the model split function
results2<- by(data = trends, INDICES = trends[,"year"], FUN = function (y){
qmat<- unique(y[ ,c("item","domain")])
qmat<- data.frame ( qmat[,"item", drop=FALSE], model.matrix(~domain-1, data = qmat))
spl <- splitModels ( qMatrix = qmat, nCores = 1)
dat <- reshape2::dcast(y, idstud~item, value.var="value")
def <- defineModel(dat=dat, splittedModels = spl, id="idstud", software="tam")
run <- runModel(def)
res <- getResults(run)
return(res)})
lErrors2<- multiEquatError(results2[[1]], results2[[2]], results2[[3]], difBound = 0.64)
# dependent DIF
lErrDif2<- multiEquatError(results2[[1]], results2[[2]], results2[[3]], difBound = 0.64, dependentDIF =TRUE)
# direct linking 1 to 3 (1 is reference)
it1 <- itemFromRes(results2[[1]])
eq1.vs.3<- equat1pl(results2[[3]], prmNorm = it1[,c("item", "est")], difBound = 0.64, iterativ = TRUE)
# replace 'direct' linking error with 'indirect' linking error from 'multiEquatError()'
eq1.vs.3<- replaceLinkingError (equatingList=eq1.vs.3, multiEquatError_output=lErrors2)
################################################################################
### Example 3: Jackknife linking for three measurement and two domains ###
################################################################################
# we reuse the previously created object 'results2' here
allItems<- rbind(itemFromRes(results2[[1]]), itemFromRes(results2[[2]]), itemFromRes(results2[[3]]))
allItems<- unique(allItems[,"item"])
tl.frame<- data.frame (testlet = substr(allItems,1,3), item = allItems, stringsAsFactors = FALSE)
# repeat the linking from example 2
jkErr2 <- multiEquatError(results2[[1]], results2[[2]], results2[[3]], difBound = 0.64, testletStr = tl.frame)
################################################################################
### Example 4: Linking for three item parameter lists ###
################################################################################
# use three item parameter lists for equating
# borrow item parameter data from the 'sirt' package
data(data.pars1.rasch, package="sirt")
# use the first three item parameter lists
e1 <- subset ( data.pars1.rasch, study == "study1")[,c("item", "b")]
e2 <- subset ( data.pars1.rasch, study == "study2")[,c("item", "b")]
e3 <- subset ( data.pars1.rasch, study == "study3")[,c("item", "b")]
multiEquatError(e1, e2, e3)
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