572 MEMOIRS NATIONAL ACADEMY OF SCIENCES. [Vol.xv. 



The first five tables are reciprocally exclusive; no single case occurs in more than one table. 

 They can be combined on any scheme of regressions that seems desirable, provided the statistician 

 is willing to admit that the beta score of a man recalled from alpha to beta is the preferable 

 measure, and the score in individual examination of a man recalled from either of the group 

 examinations is also preferable to his score in the group examination. The printing of the 

 alpha and beta scores of men taking individual examinations or of the alpha scores of men 

 taking beta is prohibited by lack of space. The sixth and seventh tables do, however, give 

 complete distributions for alpha and beta for any one that is interested in an analysis of these 

 examinations alone; and tables 3, 4, and 5 are similarly complete for each of the individual 

 examinations. In some instances the number of cases falling in some of these seven fundamental 

 tables is so small as to be negligible (for example, performance scores of negroes, who were 

 practically always given Stanford-Binet) . In such cases the table is omitted. 



The work of the various members of the staff of the Section of Psychology has been so 

 closely interrelated, assistance has been so frequently rendered, and authors have so frequently 

 submitted to compromises or to revisions of their work that it is not possible to assign either 

 credit or responsibility for the chapters of this part with any degree of accuracy. The Hollerith 

 analysis was under the immediate supervision of Capt. Boring, who has also prepared this 

 chapter and exercised with Maj. Yerkes editorial supervision over Part III. 



Chapter 2 presents in the mam the statistical work of Mr. Brown and Lieut. May, which 

 has already been referred to. The data on forms of alpha were prepared by Miss Cobb. The 

 Section of Psychology is indebted to Prof. Karl Pearson of the University College, London, 

 for considerable statistical work on the regression curves of alpha and beta, which are also 

 presented in these chapters. Unfortunately, these curves were received at a time which 

 rendered their full utilization in the general scheme of treatment difficult. 



It is rather important that camps should be compared, one with another, since (cf. tables 

 6 and 7 and relevant discussion) camp differences may readily be reflected in differences 

 between other groups and lead to erroneous interpretations. This comparison, however, 

 involves the application of the scheme of combination which was completed too late for use. 

 Lieut. Lincoln has made the comparison, however, upon a more superficial basis. 



The original selection of Group II was made with the intention of determining intelligence 

 averages for the various States. It was found on a comparison of the returns from different 

 camps, however, that differences between camps were very great indeed. Since a single State 

 was for the most part selected from a single camp, it is practically impossible to isolate dif- 

 ferences between States from camp differences. It may be that a detailed study would reveal 

 certain States examined in like camps and therefore comparable. The results are important 

 and, since the pressure of time would render anything but a most inadequate treatment 

 impossible, it has seemed better to omit statistical treatment altogether, rather than to run the 

 risk of factitious conclusions. 1 



The same argument applies to a less extent to differences in nativity of foreign-born 

 recruits. Lieut. Lincoln has, however, found time to deal with this subject briefly. The 

 data on the relation of intelligence ratings to age were brought together by Lieut. Lincoln; 

 those on the relation to physical factors by Dr. Hayes. Miss Cobb has prepared the chapters 

 on literacy, schooling, and the relation to the number of years that foreign-born recruits have 

 been in the United States. Capt. Elliott began the study of the intelligence of the negro, 

 which was completed by Lieut. Metcalf. Lieut. Lincoln has dealt with the problem of the 

 rank of officers, with the officers' training camps, noncommissioned officers' schools, and the 

 Students' Army Training Corps, and in general with disciplinary cases. Maj. Foster prepared 

 the chapter on arms of the service. The chapter on the relation of intelligence rating to 

 occupation was begun by Dr. Bridges and completed by Capt. Paterson. The description of 

 the general intelligence of the draft and its relation to discharge or rejection from the Army 

 has been made jointly in the office on the basis of data brought together by Miss Cobb. 



1 Cf. chap. 5, page 681. 



