306 MEMOIRS NATIONAL ACADEMY OF SCIENCES. rvo L . xv, 



Section 2. — The individual examination. 



During the two days before the committee's recess and while the group examination mate- 

 rial was in press the committee discussed methods of individual examination, giving special 

 attention to the possibility of employing abbreviated scales. N. J. Melville and E. A. Doll were 

 both called into conference because of their work with the abbreviated Binet. 



Immediately after this conference the preparation of methods for individual examining was 

 undertaken. It was believed that such examinations would be necessary for the men ranking 

 lowest on the group scale, for the highest 5 or 10 per cent, and for those whose scores indicated 

 that they were irregular or atypical. It was assumed further that the lowest group would be 

 made up in part of genuine subnormals and in part of foreigners and others handicapped by 

 illiteracy. It was agreed, therefore, that the methods of individual examination should be 

 worked out with special reference to subnormals, supernormals, foreigners, and psychotics. 

 Tentatively, Yerkes, Goddard, and Haines were charged with the formulation of tests for 

 illiterates and psychotics; Whipple and Bingham, for superiors; and Wells and Terman, for 

 subnormals. As it worked out, however, the contributions of the various members were not 

 governed to any great extent by these assignments. 



The question may be raised why the committee did not adopt one or more of the standard- 

 ized intelligence scales in current use instead of undertaking the preparation of new methods. 

 Perhaps the wisdom of the committee's decision is open to question in view of the fact that the 

 methods prepared at this time were soon abandoned in favor of the Yerkes-Bridges point scale 

 and the Stanford-Binet scale. Among the considerations which influenced the committee 

 were the following: 



(1) That current scales were not sufficiently "coach-proof"; (2) that new sets of tests 

 could probably be devised which would give a larger variety for choice and render the method 

 of individual examination more flexible than current methods and more readily adaptable to 

 particular types of subjects; (3) that new tests would escape the prejudice entertained by many 

 against the intelligence scales in general use. 



Before undertaking to make a selection of tests it was agreed that the tests chosen should 

 satisfy the following criteria : (1) They should be valid measures of intelligence; (2) reasonably 

 "coach-proof"; (3) not too susceptible to practice effects; (4) unfavorable to malingering; 

 (5) interesting; (6) with responses unambiguous, definite and easily scored, and the verbal 

 element reduced to a minimum; (7) little influenced by schooling; (8) brief; and (9) using 

 materials that are simple, convenient, and inexpensive. 



In order to make the individual examination as nearly "coach-proof" as possible, it was 

 agreed to limit the selection of tests in most cases to those for which five equivalent series of 

 items could be devised. With this and the other criteria in niind, approximately 50 different 

 tests proposed by various members of the committee were subjected to critical consideration. 

 From these, 21 were selected, as follows: 



Test A. Painted cuhe. — This test 1 was suggested to the committee by Goddard. Yerkes 

 and Goddard modified the original test by arranging a series of steps of gradually increasing 

 difficulty and by preparing suitable directions for giving and scoring. 



Test B. The cloclc test. — This is the well-known Binet test of reversing the hands of the 

 clock, 2 supplemented by the test of telling time. Three steps of graded difficulty were proposed: 

 (1) Telling time; (2) reversing hands of clock, with clock in view; (3) same, with no clock in 

 view. Alternative forms were prepared by Wells. The test of telling time has been shown by 

 Gertrude Hall 3 to give a high correlation with Binet mental age. 



Test C. Cuhe imitation. — This is the Knox test 4 as adapted by Yerkes, who also prepared 

 the instructions. The test as given by Knox has proved valuable in testing immigrants. 



1 For history see Jour. Educ. Psy., March, 1917, pp. 176-17S. 



* Detailed reference to the various tests originated or elaborated by Binet seems superfluous. Information regarding these can be located con- 

 veniently in the following volume: Binet, A,, and Simon, Th. The Development of Intelligence in Children. Translated by Kite, E. S., 1916. 

 > Eleven Mental Tests Standardized. Eugenics and Social Welfare Bulletin No. 5, New York State Board of Charities. 

 < Knox, H. A. A Scale Based on the Work at Ellis Island for Estimating Mental Defect. J. Amer. Med. Assoc., vol. 62, 1914, p. 742. 



