difR-package: Collection of methods to detect dichotomous differential item functioning (DIF) in psychometrics


The difR package contains several traditional methods to detect DIF in dichotomously scored items. Both uniform and non-uniform DIF effects can be detected, with methods relying upon item response models or not. Some methods deal with more than one focal group.

Methods currently available are:

  1. Transformed Item Difficulties (TID) method (Angoff and Ford, 1973)

  2. Mantel-Haenszel (Holland and Thayer, 1988)

  3. Standardization (Dorans and Kullick, 1986)

  4. Breslow-Day (Aguerri et al., 2009; Penfield, 2003)

  5. Logistic regression (Swaminathan and Rogers, 1990)

  6. Lord's chi-square test (Lord, 1980)

  7. Raju's area (Raju, 1990)

  8. Likelihood-ratio test (Thissen, Steinberg and Wainer, 1988)

  9. Generalized Mantel-Haenszel (Penfield, 2001)

  10. Generalized logistic regression (Magis, Raiche, Beland and Gerard, 2011)

  11. Generalized Lord's chi-square test (Kim, Cohen and Park, 1995).

The difR package is further described in Magis, Beland, Tuerlinckx and De Boeck (2010).


Package: difR
Type: Package
Version: 4.6
Date: 2015-04-24
Depends: R (>= 2.8.0), lme4, ltm
License: see file LICENSE


Sebastien Beland
Collectif pour le Developpement et les Applications en Mesure et Evaluation (Cdame)
Universite du Quebec a Montreal
sebastien.beland.1@hotmail.com, http://www.cdame.uqam.ca/
David Magis
Department of Education, University of Liege
Research Group of Quantitative Psychology and Individual Differences, KU Leuven
David.Magis@ulg.ac.be, http://ppw.kuleuven.be/okp/home/
Gilles Raiche
Collectif pour le Developpement et les Applications en Mesure et Evaluation (Cdame)
Universite du Quebec a Montreal
raiche.gilles@uqam.ca, http://www.cdame.uqam.ca/


Aguerri, M.E., Galibert, M.S., Attorresi, H.F. and Maranon, P.P. (2009). Erroneous detection of nonuniform DIF using the Breslow-Day test in a short test. Quality and Quantity, 43, 35-44.

Angoff, W. H., and Ford, S. F. (1973). Item-race interaction on a test of scholastic aptitude. Journal of Educational Measurement, 95-106.

Dorans, N. J. and Kullick, E. (1986). Demonstrating the utility of the standardization approach to assessing unexpected differential item performance on the Scholastic Aptitude Test. Journal of Educational Measurement, 23, 355-368.

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

Kim, S.-H., Cohen, A.S. and Park, T.-H. (1995). Detection of differential item functioning in multiple groups. Journal of Educational Measurement, 32, 261-276.

Lord, F. (1980). Applications of item response theory to practical testing problems. Hillsdale, NJ: Lawrence Erlbaum Associates.

Magis, D., Beland, S., Tuerlinckx, F. and De Boeck, P. (2010). A general framework and an R package for the detection of dichotomous differential item functioning. Behavior Research Methods, 42, 847-862.

Magis, D., Raiche, G., Beland, S. and Gerard, P. (2011). A logistic regression procedure to detect differential item functioning among multiple groups. Unpublished manuscript.

Penfield, R. D. (2001). Assessing differential item functioning among multiple groups: a comparison of three Mantel-Haenszel procedures. Applied Measurement in Education, 14, 235-259.

Penfield, R.D. (2003). Application of the Breslow-Day test of trend in odds ratio heterogeneity to the detection of nonuniform DIF. Alberta Journal of Educational Research, 49, 231-243.

Raju, N. S. (1990). Determining the significance of estimated signed and unsigned areas between two item response functions. Applied Psychological Measurement, 14, 197-207.

Swaminathan, H. and Rogers, H. J. (1990). Detecting differential item functioning using logistic regression procedures. Journal of Educational Measurement, 27, 361-370.

Thissen, D., Steinberg, L. and Wainer, H. (1988). Use of item response theory in the study of group difference in trace lines. In H. Wainer and H. Braun (Eds.), Test validity. Hillsdale, NJ: Lawrence Erlbaum Associates.

See Also

Other useful packages can be found in the R Psychometric task view.

Questions? Problems? Suggestions? or email at ian@mutexlabs.com.

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