A Case for Professional Judgment When Combining Marks

Issues raised in a paper by Moss (1977) in this Journal, are discussed in this paper which describes a strategy for comparing and combining marks on the basis of rational analysis and professional judgment. Consideration is given to the interpretation and implications of mean values, standard deviations, correlations and shapes of mark distributions. The data presented by Moss (1977) are analysed and procedures are discussed which discriminate between nominal and effective weightings (Willmott and Hall, 1975) with reference to the effects of standard deviation and correlation. This approach may also be used for combining sets of marks which are not equally weighted and is potentially more useful to the teacher than standardising procedures. In some circumstances combination may be judged inappropriate and association of marks (in a profile) might be the preferred procedure. All such procedures demand the professional judgment and expertise of teachers, to utilise fully the information available in the raw marks of student performance.