SINGLE TESTS AND SERIES OP TESTS 17 



Thus, in an earlier stage of his work Binet (2) be- 

 lieved that the essence of intelligence was capacity 

 to adjust attention : for this reason he used tests of 

 attention, like the cancellation of letters in a speci- 

 fied text (the Bourdon test), the copying of sentences, 

 the esthesiometer (Binet regarded the discrimina- 

 tion of two near-lying compass-points as a phenom- 

 enon of attention, not of sensation), the sorting 

 of cards containing the alphabet, or numbers, etc. 

 In the work of Meumann (14) we note at times the 

 laying of a certain one-sided emphasis on the under- 

 standing of the abstract as being the root of intelli- 

 gence. This was why he specially recommended the 

 use in testing of the retention of abstract words. 

 Quite a number of investigators have directed their 

 attention particularly to capacity to apprehend as 

 the index of intelligence, and hence have preferred 

 to use for tests such things as the apprehension of 

 pictures or ability to perceive linguistic material of 

 different contents and extents. 



(c) We may consider as a third main class of 

 tests those patterned after familiar pedagogical 

 tasks. There are, indeed, certain school activities 

 that admit of relatively precise grading, since they 

 can be rated both in terms of quantity (amount done 

 within a given time) and in terms of quality (fre- 

 quency of mistakes). Those schoolroom tasks are 

 most obviously adaptable for psychological pur- 

 poses within which the course of activity is fairly 

 homogeneous, e. g., the computation of specified 

 arithmetical problems, writing from dictation, com- 

 mitting to memory of vocabularies and poems, and 

 all these tasks have, in fact, been used for testing in- 



