This R Code is used with the Item_Bank_berglunz data. This is to create simulated data with differing levels of test difficulty. Test difficulty is modified by changing the R syntax. To create an easier test, modify the "tpc=0" line. This is an item selection parameter and measured in logits. For an easier test, for example, change "tpc=0" to "tpc=.451." The study associated with this data is "Self-Efficacy in the CAT Environment."