A test or protocol may consist of a series of subtests. You want each person to have a separate measure on each subtest, but in the same frame of reference as the overall test measures.

 

First, code each item in its item label with what subtest it belongs to.

 

A. Using DPF.

 

1. Analyze all the data together.

 

2. Reporting of subtests.

Reporting subtest items: In an overall analysis, the items of individual subtests can be reported after applying ISELECT= from the Specification pull-down box.

 

Reporting subtest person measures: a measure for each person on each subtest can be obtained by specifying the subtest identification column in the item label in DPF= and producing Table 31 or the DPF plot.

 

B. Using separate analyses.

 

1. Analyze all the data together.  Produce an IFILE=if.txt. Produce a PFILE= for global measures.

 

2. Anchor all items IAFILE=if.txt.

Select one subtest: ISELECT=subtest code

Run Winsteps

Produce IFILE= and PFILE for the subtest.

 

3. Repeat for the other subtests.