When creating an assessment question, give the option for the teacher to add a rationale for why the correct answer is correct and, in the case of multiple choice, why another item choice is the wrong answer.  Give teachers the option of whether they would like to display this rationale to students during the test or only after.

Such rationale would allow a student to self-assessment on an item, and if they get the answer wrong, they could read the rationale and learn from their mistake.

Currently, onCampus allows the teacher to give individual comment/feedback to each student during the assessment grading process, but this is only available AFTER the assessment is grade, and often the teacher might need to be explaining the same rationale again and again to multiple students.  The "idea" described above would allow a teacher to articulate the rationale once as the questions are created.