_V. How do the various measures of intelligence compare with one another, and what is the reliability of these various measures?_ Frequent studies have been made of the relation between teachers' estimates of the general intelligence of pupils and their intelligence as shown by their performance in psychological tests. The teacher's estimate is perhaps very likely to be based on that sort of intelligence which shows itself in academic performance only, since in many cases the acquaintance is limited to contact in class room and laboratory. In our own case we have teachers' estimates only in the form of the actual class records. These are, then, not estimates of general intelligence in the strict sense, but are conditioned presumably for the most part by the student's performance in the class room. The academic marks were reported according to a letter system, in which A means "very good," B means "good," C means "fair," D means "poor" and F means "failed." Having secured these marks for all the students in English, German, Logic, Psychology, Economics and History, we averaged the marks for each student, by giving A, B, C, D and F values of 90, 80, 70, 60 and 50. This gave us final averages for all the students, on the basis of which averages they were arranged in order of merit, the two groups being separately treated. We have now the three following measures of intelligence: a. The results of the psychological tests. b. The opinion of fellow students. c. The academic records. The correlations between these various measures are given in the following tabulation: TABLE 7 SHOWING THE CORRELATIONS BETWEEN VARIOUS MEASURES OF INTELLIGENCE -------------------------------------------------------- | 25 | 25 |Juniors|Seniors ----------------------------------------+-------+------- Correlation of psychological tests with | | estimated Intelligence | .70 | .53 Correlation of psychological tests with | | Academic Records | .42 | .57 Correlation of Academic Records with | | estimated Intelligence | .22 | .37 --------------------------------------------------------