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MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



[Vol. XV, 



this procedure rendered the adequacy of the beta examination unquestionable, since it was 

 not certain at that time that foreign-born men were not under a certain handicap even in beta 

 because of language deficiencies. Table 8 summarizes Group X. 



Table 8. — Group X. Special experimental group. 



Number of cases in Group X, 1,047 English-speaking, but otherwise unselected, men from the white draft, who took 

 both alpha and beta examinations for correlational purposes; 653 of these men also took the Stanford-Binet examina- 

 tion. Table shows the distribution by camps. 



Taking alpha, beta, and Stanford-Binet examinations: 



Camp Custer 64 



Camp Dix 93 



Camp Jackson 102 



Camp Lee 105 



Camp Meade 91 



Camp Pike 67 



Camp Upton 54 



Camp Wadsworth 41 



Camp Wheeler '. 36 



Total 653 



Taking alpha and beta examinations: 



Camp Custer 15 



Camp Greenleaf 233 



Camp Pike 36 



Camp Taylor 65 



Camp Upton 17 



Camp Wheeler 28 



Total : 394 



Total Group X 1, 047 



This group is a very important group, because upon it most of the analysis of tests and 

 the statistical treatment for the combination of different types of examination has been based. 

 It forms the foundation of the immediately subsequent chapters of this part (q. v.). 1 



Summary. — Table 9 gives a summary of all groups. It will be noted that there is available 

 altogether a sample of 96,354 records of white recruits, a sample which is fairly representative 

 of the country, for Groups I, II, and III give approximately the same form of distribution. 

 The total of records for negro recruits is 25,392, of which 5,400 are for northern negroes only. 

 The sample for white officers is 15,528, and for white established organizations 24,205. The 

 approximate total of the principal sample is 162,526. 



Table 9. — Summary of principal sampling. 

 Number of cases in various groups of principal sample: cf. tables 1 to 8. 



1 See also the use of this group and its description in Part II, chapter 7, pages 379 to 395. 



