Abstract:

Cognitive Diagnostic Multistage Testing (CD-MST) is a new testing mode which combines MST with CDA. It has some advantages, such as improving instruction, allowing administers to check the pre-assembled test forms, allowing the examinee to review and revise answers. The initial stage module assemble methods is an important part for CD-MST. It is presented seven initial stage module assemble methods, they are Random method, Item Selection method, R* Matrix method, CTTID method, CDI method, CTTIDR* method and CDIR* method. 1) Random method means that select first stage items from item bank randomly, this method does not consider item parameters and attributes. It is easy and fast.2) Item selection method is first to randomly assign a knowledge state to examinee, and then select the initial stage items according to item selection indices (such as PWKL, SHE). 3) R* matrix method is to select initial items from R-matrix. 4) CTTID method means that select high discriminatory items for the first stage. In DINA model, high discriminatory items are the items slipping and guessing parameters smaller.5) CDI method is presented by Henson and Douglas (2005), it’s another item discrimination index, it considers item parameter and attribute.6) Item parameter and R matrix are the important elements which can influence the efficiency of testing, so here we consider discrimination and R matrix simultaneously to select first stage items, CTTIDR* method and 7) CDIR* method are from this consideration. A simulation research was used to verify these methods of CD-MST. CDM was DINA model, the number of examinee was 3000, item bank was 1240, the number of attributes was 5, stage number of CD-MST was 3. PCCR and ACCR were the evaluation indices. The quality of item bank was a contributory factor. The results showed that after the initial stage, under each of the quality of item banks, the PCCR of the methods with R* matrix were higher than others. When the tests were finished, CTTIDR* method was also higher than others, it had obvious advantage. CD-MST is an efficient application of MST in CDA. It is necessary to study many issues of CD-MST, the initial stage module assemble method is one of them. Some of the seven methods we presented here are effectively and exactly. These methods can also extend to CD-CAT.

Key words: CDA, MST, CD-MST, initial stage module assemble methods