The Data worksheet for this test is on display here in Excel 2010. The Excel ribbon is showing the Lertap tab with its five groups of icons, from "Basic options" to "Other menus". (More information on Lertap Data worksheets is here.)
There were two nominal, or categorical, variables: Standard (column 2) and Gender (column 4). A student's age in years is found in column 3. Item responses begin in column 5 and extend through column 28.
Each item presented four options to the students. The response codes used for the options were {A,B,C,D}. If a student did not answer an item, or selected more than one option, a "response" code of 9 was used.
Above we can see that the first student selected option A for the first item (I1), B for the second (I2), third (I3), and fourth (I4) items, and, on I5, D.
The second student did not answer I1, I3, and I9. The sixth student, D7S1206, did not answer any of the first five items.
There were 3,389 students when I started out. This dropped to under 3,000 after I had cleaned the data -- you'll see what I did a bit later.
Next up, the CCs worksheet.