(1) In function 7, qimk is “the score forstimulus feature k in component m for item I”. When we observe figure 3, the author explain the qimk in this example is the indicators which define specific skills within the category. Then we know this variable was generated as a continuous variable in simulation study. My question is that I though qimk is the feature for item i involved skill k in component m and it is the parameter for items. For example, in figure 3, the standard “Algebra” include the three benchmarks and there are two skills (attributes) involving this test. The features indicate attributes should be found and given a value for each item. However how to use the continuous variables for items to do the diagnoses of the attributes level which examinee has. I think it is more reasonable to set this variable as person’s variable.
(2) For DIF issue, Is it possible to detect DIF at the structure of qimk for which benchmark which was judged by experts?