National Academy of Sciences. (1921). Performance in intelligence examinations as related to military efficiency. In R. M. Yerkes (Ed.), Memoirs of the National Academy of Sciences, Vol. xv: Psychological examining in the United States Army (pp. 453-468). Washington, DC, US: Washington Government Printing Office.
http://dx.doi.org/10.1037/10619-017
The amount of weight that should be placed upon intelligence ratings, as determined by psychological examination, in the selection of men for military duty, depends upon the degree to which examination ratings are prognostic of military value. The present chapter discusses the relation of performance in examinations alpha and beta to military efficiency, as such efficiency is estimated by US Army company commanders. All of the alpha tests show a rather satisfactory degree of differentiation between groups of considerable differences in military efficiency. It is possible that greater refinement in the definition of standards of military efficiency and in the application of them would make possible a better selection of alpha tests than exists at present. So long as such standards remain as vague and undefined as the present study indicates them to be there is little ground for regarding one alpha test as considerably more or considerably less efficient than another, always excepting test 5, which seems consistently from every point of view the least effective. In general the beta tests show the same tendency to vary in sharpness of differentiation in the different groups compared. (PsycINFO Database Record (c) 2016 APA, all rights reserved)