Nov. 1918, June and Nov. 1919 June 1920 IQ and AQ .925 .946 IQ and VQ .924 .946 IQ and RQ .936 .953 IQ and CQ .941 .955 The limits of the June, 1920 _r_’s are naturally somewhat larger than the others since two forms of tests (except the Binet) were used; the unreliability of the quantitative indices is therefore lower and hence the correlation with IQ may be larger. The correlations in 1920 of another group—the whole school except Grade III—are reproduced in Table 5. Grade III was excluded since here there had as yet been little chance to push the _r_’s. Partials were obtained with these data (Table 6). Little faith may be placed in the relative sizes of these partials, much because the _r__{VQ.RQ} is here only .73 and, in the data presented in Table 3, it is .87. This is due to the fact that the data in Table 3 cover all periods (2 years) while those in Table 5 cover only one. This difference has comparatively slight influence on our general conclusions; but it makes a huge difference in the correlation of RQ and VQ when IQ is rendered constant, whether the one or the other set of data is used. Moreover, the whole logic of arguing for general factors by reduction of partial correlations from the original _r_ has been called gravely into question in Godfrey H. Thomson’s recent work on this subject: “The Proof or Disproof of the Existence of General Ability.” Thomson shows that partial correlation gives one possible interpretation of the facts, but not an inevitable one. Thus we cannot say that because RQ and IQ and RQ and AQ are highly correlated, correlation of IQ and AQ is dependent upon RQ. We can say, however, that it is likely to be. IQ and AQ may be correlated by reason of inclusion of some element not included at all in RQ. The higher the correlations which we deal with the less we need worry about this, and of course correlations of unity exclude any such consideration. TABLE 5 INTERCORRELATION OF ALL QUOTIENTS IN JUNE, 1920. ALL CHILDREN EXCLUSIVE OF GRADE 3 ARE HERE REPRESENTED The P.E.’s are all less than .05 _N_ = 81 Arithmetic Vocabulary Reading IQ Quotient Quotient Quotient Arithmetic Quotient .733 Vocabulary Quotient .837 .628 Reading Quotient .758 .694 .734 Completion Quotient .821 .770 .825 .801