The proportion of B and C items
that were correct was similarly determined by dividing the
number of items to which a student had responded B or C
and had subsequently answered correctly by the total
number of items to which they had responded B or C.
These items could be considered “false negatives”—
students’ KS responses indicated that they did not believe
they could answer these questions correctly, and yet they
did so on the assessment. Results of these calculations are
shown, broken out by student ability level, in Fig. 4. Note