432 



MEMOIRS NATIONAL ACADEMY OF SCIENCES. 



BETA CORRELATIONS. 

 Group. 



[Vol. XV, 



Alpha before beta ( Meade) 



Beta before alpha (Meade) 



MacArthur (all beta) 



Beauregard (all beta) 



Co. H, Fifth Battalion, Infantry Replacement Camp (MacArthur) 



Thus the elimination of the factor of " selectedness " of groups does not eliminate the 

 differences in degree of correlation between ratings and scores. These differences might be 

 due to: 



(a) Qualitative differences in standards by which the men of the different groups were rated. 



(b) Nearer approach to accuracy in the ratings of some groups than in others, because of 

 officers' longer acquaintance with men, or differing degrees of ability to "size up" men. 



(c) Lowering of correlation by throwing together in the same table a considerable variety 

 of ratings, as ratings from several different officers. It will be seen from table 81 that subjective 

 ratings are essentially the class marks of ranked classes, and not measures upon an absolute 

 scale. Therefore if these class marks are averaged we obtain different means from different 

 officer's ratings of the same group of men. 



As regards (a) it is to be noted that the correlation of total alpha scores with ratings in 

 the MacArthur group is lower than the similar correlation for the Beauregard group, while the 

 contrary is true of beta total scores correlations. Owing to the imperfect standardization of 

 procedure in the beta examination, this should be taken as merely suggestive of qualitative 

 differences in rating standards, however. 



With respect to (b) above we have the information that the Camp Meade ratings were made 

 by officers who had known their men for at least three months, while the great majority of 

 MacArthur and Beauregard cases had been under the observation of their officers for six weeks 

 or less. This point will be discussed at greater length later. 



Further investigation of the point raised in (a) above, and any study of the problem of 

 (c) requires detailed consideration of the correlations of separate alpha and beta tests with 

 ratings, in the groups already cited with reference to total scores, and also in smaller groups 

 rated by the same officer or officers throughout. 



Tables 92 and 93 give correlations and standard deviations of the separate tests of alpha 

 and beta, respectively. The standard deviations of scores in alpha tests indicate two things at 

 once — viz, that the groups differ appreciably in "selectedness" in the same way as indicated 

 by the total scores, and that there is little if any qualitative variation among groups. The 

 only evidence against the latter conclusion is the exceptional standard deviation of test 4, 

 beta before alpha group, which is larger than the standard deviation of test 4 for the alpha 

 before beta group, while in all other tests the standard deviations are greatest for the alpha 

 before beta group. This divergence is very small, however. 



