This has been proved repeatedly by careful tests, and is evident from the erratic clustering of grades around arbitrary points on the scale in every school where the attempt is made to use a scale with thirty or more divisions.
Individual instructors, in defense of their extreme variations from the mean proportion of high and low grades, often assert that the students who elect their subjects are much better than the students who elect other courses. Figs. 2 and 8 seem to indicate that quite the opposite is the truth. The poorer students elect a larger proportion of their work than the better students from courses in which the number of high grades given is relatively large. The better students elect a larger proportion of their work than the poorer students from courses in which the number of low grades given is relatively large. Furthermore, it is possible to show that the variations in grade distribution do not represent equal variations in the abilities of the groups of students concerned. We can demonstrate this by comparing the grades attained by a large number of students in certain departments with the grades attained by these same students in other departments.
Such a study is summarized in Table III. It exhibits the record in Harvard College of 363 men from twelve classes who later graduated with honor from the Harvard Law and Medical Schools. It gives the exact number of students receiving in a given subject a rank higher than their median rank for all subjects. Thus it appears that English, fine arts, mathematics, classics and modern languages, in the order named, constitute a group in which the grades assigned in this institution are comparatively low. On the other hand, natural sciences, philosophy and history and political sciences, in the order named, make up a group in which the grades assigned are comparatively high. At the two extremes stand English, in which 86 per cent, of the students received lower than their median rank in all subjects, and natural sciences, in which 71 per cent, of the same students received higher than their median rank. Furthermore, this table does not represent the extreme variations within departments. The eccentricities of the hardest markers in English and the easiest markers in natural sciences are here offset by the other markers in each department. We must conclude, therefore, that the diverse distribution of grades shown in the figures can not be justified by the unsupported assertion that the students electing certain subjects have far more ability than the students electing other subjects.
The question arises whether it is possible to supplant the personal equation as the chief factor in the awarding of college grades by scientific guidance? The immediate answer to this question depends on whether the distribution of mental traits in groups of individuals follows any regular law—and for the present on nothing else. The ulti-