The question of the chapter title immediately begs other questions, namely, ‘How is student performance to be judged? Against what standard are we to judge student marking? With what do we compare student grades?’ There seem to be two main contenders for a standard against which to judge student grading, though other less frequently employed possibilities also exist. Student marks are most often compared with teacher marks for the same piece of work. However, student marks may also be compared with other marks awarded by teachers for different pieces of work. It is the former, teacher-student comparison, that is most commonly used when teachers or researchers wish to be sure that student participation in assessment is either reliable or valid.