THE METHOD OF AGE GRADATION 59 



cases of pedagogical advance seem to be more com- 

 mon. Betardations are, however, quite frequent in 

 consequence of non-promotion, long illness, etc., and 

 sometimes they reach a considerable degree. 



Comparisons of pedagogical and mental age have 

 been made by Binet and by Goddard. 



TABLE VI. 

 RELATION OF PEDAGOGICAL AND MENTAL AGE (BINET). 



-Mental Age- 



Pedagogical Age Retarded At Level Advanced Total 



Retarded 14 9 1 24 



Normal 16 33 16 65 



Advanced 5 7 12 



Total 30 47 24 101 



Binet (36, p. 162) presents a distribution-table for 

 101 pupils and regards the agreement as tolerably 

 satisfactory (Table VI). In fact, we do note that 

 there are no paradoxical cases : no one of the children 

 with mental retardation is pedagogically advanced, 

 and only a single mentally advanced child turns out 

 to be pedagogically retarded (and that case may be 

 conditioned by illness). Yet in the remainder of the 

 Table there are divergences of considerable magni- 

 tude: only a scant third of the mentally advanced 

 are also pedagogically advanced; less than half of 

 the mentally retarded are likewise pedagogically re- 

 tarded, while, of the pupils 'at age' pedagogically, 

 one quarter surpass and another quarter fall short 

 of the mental level of their age. 



An exact computation of these relations can be 

 made by using the method of contingency. 15 Con- 



15 The formula for it is developed in another of my treatises 

 (1, 308 ff.). 



