mantelHaenszel {difR}R Documentation

Mantel-Haenszel DIF statistic

Description

Calculates the Mantel-Haenszel statistics for DIF detection.

Usage

 mantelHaenszel(data, member, correct=TRUE, anchor=1:ncol(data))
 

Arguments

data numeric: the data matrix (one row per subject, one column per item).
member numeric: the vector of group membership with zero and one entries only. See Details.
correct logical: should the continuity correction be used? (default is TRUE).
anchor a vector of integer values specifying which items (all by default) are currently considered as anchor (DIF free) items. See Details.

Details

This command computes the Mantel-Haenszel (1959) statistic in the specific framework of differential item functioning. It forms the basic command of difMH and is specifically designed for this call.

The data are passed through the data argument, with one row per subject and one column per item. Missing values are not allowed.

The vector of group membership, specified with member argument, must hold only zeros and ones, a value of zero corresponding to the reference group and a value of one to the focal group.

By default, the continuity correction factor -0.5 is used (Holland and Thayer, 1988). One can nevertheless remove it by specifying correct=FALSE.

Option anchor sets the items which are considered as anchor items for computing Mantel-Haenszel statistics. Items other than the anchor items and the tested item are discarded. anchor must hold integer values specifying the column numbers of the corresponding anchor items. It is primarily designed to perform item purification.

Value

A vector with the values of the Mantel-Haenszel DIF statistics.

Author(s)

Sebastien Beland
Centre sur les Applications des Modeles de Reponses aux Items (CAMRI)
Universite du Quebec a Montreal
sebastien.beland.1@hotmail.com
David Magis
Research Group of Quantitative Psychology and Individual Differences
Katholieke Universiteit Leuven
David.Magis@psy.kuleuven.be, http://ppw.kuleuven.be/okp/home/
Gilles Raiche
Centre sur les Applications des Modeles de Reponses aux Items (CAMRI)
Universite du Quebec a Montreal
raiche.gilles@uqam.ca, http://www.er.uqam.ca/nobel/r17165/

References

Holland, P. W. and Thayer, D. T. (1988). Differential item performance and the Mantel-Haenszel procedure. In H. Wainer and H. I. Braun (Ed.), Test validity. Hillsdale, New Jersey: Lawrence Erlbaum Associates.

Mantel, N. and Haenszel, W. (1959). Statistical aspects of the analysis of data from retrospective studies of disease. Journal of the National Cancer Institute, 22, 719-748.

See Also

difMH, dichoDif

Examples

 # Loading of the verbal data
 data(verbal)

 # With and without continuity correction
 mantelHaenszel(verbal[,1:23], verbal[,25])
 mantelHaenszel(verbal[,1:23], verbal[,25],correct=FALSE)
 
 # Removing item 6 from the set of anchor items
 mantelHaenszel(verbal[,1:24], verbal[,26], anchor=c(1:5,7:24))
 

[Package difR version 1.1 Index]