Grading Without Guesswork

STUDENTS are graded on their characteristics in much the same way that eggs are. Eggs receive independent grades on external size, shape, color, fluidity, opacity, internal strength of yolk, yolk color, and smell. All of these grades are combined to obtain a composite, which is not necessarily an average. For example, a very rotten egg, which is Grade A on most of the other characteristics, might average Grade C, but could not legitimately be sold as Grade C. Yet many professors who have taught courses consisting of both lecture and laboratory, have actually averaged the scores of the two components, and then wondered why two students of markedly different ability have equal average scores. This paper will present a few of the fundamentals of combining independent scores to obtain a composite score. This action occurs in weighting the questions within an examination ; in combining examination, daily work, and laboratory scores for a course grade; and in averaging course grades for the dean’s list or for an all-university standing. A score refers to the numerical mark made by a student on an