22 PSYCHOLOGICAL METHODS OF TESTING INTELLIGENCE 



However, everyday life shows that we can disre- 

 gard these qualitative differences and nevertheless 

 may characterize the general grade of intelligence 

 that a man possesses. When we do this we make, 

 even unconsciously, certain compensations : two per- 

 sons may have an intelligence of the same value, but 

 of somewhat different kinds. In tests there must be 

 introduced a kind of systematic compensation like 

 this. We must test the different phases of the activ- 

 ity of intelligence and seek to construct a general 

 picture of the degree of intelligence from the differ- 

 ent results, partially accordant, partially variant as 

 they will be. 



This has given us a clear idea of what is wanted 

 in the methodics of intelligence testing. 



Negatively, it must be declared that the method 

 of isolated tests, the idea of basing everything on a 

 single test, is methodologically no better than such a 

 procedure as judging the total character of a man 

 on the strength of the single arbitrarily selected 

 symptom of his handwriting (graphology). 



Positively, three things are evident: first, series 

 of tests must be arranged that will set in play the 

 various constituent functions of intelligence; sec- 

 ondly, for this purpose there must be a wise selec- 

 tion of tests ; out of the immense number of possible 

 tests only those should be chosen that afford a de- 

 cided and a reliable symptomatic value, general ap- 

 plicability, and possibility of objective evaluation; 

 thirdly, there must be created a system by means of 

 which the several particular results of the testing 

 can be united into one resultant value, i. e., a value 

 that shows the grade of intelligence of the subject 

 objectively in an inclusive formula in which per- 



