Differential Bundle Functioning Using the DFIT Framework: Procedures for Identifying Possible Sources of Differential Functioning

A general framework for assessing differential functioning of items and tests (DFIT) was recently proposed. Both unidimensional and multidimensional tests with either dichotomous or polytomous scoring can be handled within this framework. In this study, the DFIT framework is expanded to include differential bundle functioning (DBF) as a mechanism for identifying possible sources of differential functioning. This expansion is illustrated with an empirical (reading comprehension) data set consisting of a gender comparison and a socioeconomic status comparison with 1,000 participants in each group. Bundles on this particular test that exhibited large DBF include a reading passage that favored boys over girls, possibly due to its context. The theoretical and practical implications of the use of DFIT for identifying possible sources of differential functioning are discussed.

[1]  B. Bloom,et al.  Taxonomy of Educational Objectives. Handbook I: Cognitive Domain , 1966 .

[2]  J. Stanley,et al.  Intellectually Talented Boys and Girls: Educational Profiles , 1982 .

[3]  Martha L. Stocking,et al.  Developing a Common Metric in Item Response Theory , 1983 .

[4]  Robert J. Mislevy,et al.  BILOG 3 : item analysis and test scoring with binary logistic models , 1990 .

[5]  H. Wainer,et al.  Differential Testlet Functioning: Definitions and Detection , 1991 .

[6]  William Stout,et al.  A model-based standardization approach that separates true bias/DIF from group ability differences and detects test bias/DTF as well as item bias/DIF , 1993 .

[7]  Ratna Nandakumar,et al.  Simultaneous DIF Amplification and Cancellation: Shealy-Stout's Test for DIF , 1993 .

[8]  Howard T. Everson,et al.  Methodology Review: Statistical Approaches for Assessing Measurement Bias , 1993 .

[9]  T. C. Oshima.  The Effect of Speededness on Parameter Estimation in Item Response Theory , 1994 .

[10]  Wim J. van der Linden,et al.  IRT-Based Internal Measures of Differential Functioning of Items and Tests , 1995 .

[11]  Jeffrey A Douglas,et al.  Item-Bundle DIF Hypothesis Testing: Identifying Suspect Bundles and Assessing Their Differential Functioning , 1996 .

[12]  Hua-Hua Chang,et al.  Detecting DIF for Polytomously Scored Items: An Adaptation of the SIBTEST Procedure , 1995 .

[13]  Nambury S. Raju,et al.  Development and Demonstration of Multidimensional IRT‐Based Internal Measures of Differential Functioning of ltems and Tests , 1997 .