The test is too long to finish, basically at some point the students look through the pamphlet and decide no one can finish this thing. "Retaking" misses the i

The test is too long to finish, basically at some point the students look through the pamphlet and decide no one can finish this thing. "Retaking" misses the implementation of this test, it is more akin to "I'm going to keep giving you problems as long as you are willing to sit here" kind of thing. Additionally this is the main correlation of the study. I doubt if researchers had in mind that the number of questions answered would be significant. If you told students "we are testing for number of questions answered" obv would distort the results.