The GMAT2test data set is generated data set based on parameters from Graduate Management
Admission Test (GMAT) data set (Kingston et al., 1985). First two items were considered to function differently
in uniform and non-uniform way respectively. The data set represents responses of 1,000 subjects to
multiple-choice test of 20 items. Aditionally, 4 possible answers on all items were generated,
coded A, B, C and D. The column group represents group membership, where 0 represents reference group
and 1 represent focal group. Groups are the same size (i.e. 500 per group).
data(GMAT2test)A GMAT2 data frame consists of 1,000 observations on the following 21 variables.
The first 20 columns represents answers of subject to an items of the test. The 21st column is vector of
group membership; values 0 and 1 refer to reference and focal group.
Correct answers are presented in GMAT2key data set.
Kingston, N., Leary, L., & Wightman, L. (1985). An Exploratory Study of the Applicability of Item Response Theory Methods to the Graduate Management Admission Test. ETS Research Report Series, 1985(2) : 1-64.
Drabinova, A. & Martinkova P. (2017). Detection of Differential Item Functioning with NonLinear Regression: Non-IRT Approach Accounting for Guessing. Journal of Educational Measurement, 54(4), 498-517, https://doi.org/10.1111/jedm.12158.