The GMATkey is a vector of factors representing correct answers of generated GMATtest data set based on Graduate Management Admission Test (GMAT) data set (Kingston et al., 1985).
GMAT
(Package: difNLR) :
Dichotomous Data Set Based on Graduate Management Admission Test
The GMAT 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. A correct answer is coded as 1 and incorrect answer as 0. The column group represents group membership, where 0 represents reference group and 1 represents focal group.
GMATtest
(Package: difNLR) :
Data Set Based on Graduate Management Admission Test
The GMATtest 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.
providing 
.