60 



SCIENCE 



[N. S. Vol. XLIX. No. 1255 



high altitudes. Parsons was testing the sig- 

 nificance of the duration of nystagmus after 

 rotation for future success in flying in the 

 case of naval aviators; and his negative re- 

 sults were corroborated by the writer, and sup- 

 ported by Dodge's analysis of the reaction 

 themselves. Shepard had devised and was 

 standardizing tests of observation of a modi- 

 fiable landscape. Other work helped to differ- 

 entiate the qualities of a successful flying 

 officer from those of a successful officer in 

 general. 



The formal procedure which was to go into 

 operation for the selection of some twelve 

 hundred aviation cadets per month from the 

 Students' Army Training Corps, beginning in 

 November, 1918, was in fact based in large 

 measure on work done by men of science and 

 the Personnel and Training Sections of the 

 Air Service. "Working together they had re- 

 placed the practise of selecting for flyers on 

 the basis of general officer quality, by a bill 

 of specifications of the sort of man demon- 

 strably fit to complete the course in the ground 

 school, learn to fly in a reasonable time, and 

 give promise of achievement as a flying officer 

 at the front. At the same time means were 

 provided to do this without diverting from any 

 other staff corps or from the line, men who, 

 though fit to be flyers, were still fitter for other 

 service. 



I ought, in justice to the analytic personnel 

 work, to give a wider sampling of its results, 

 but I can not resist the temptation to use the 

 few minutes remaining for two general re- 

 flections concerning psychology in relation to 

 personnel practise in general. 



The applied psychology or human engineer- 

 ing which has been developing so rapidly in 

 the last decade has learned, in the war, if not 

 before, that nothing short of the best in either 

 ideas or men can do its work. Applied psy- 

 chology is much more than cleverness and 

 common sense using the facts and principles 

 found in the standard texts. It is scientific 

 work, research on problems of human nature 

 complicated by conditions of the shop or school 

 or army, restricted by time and labor cost, 

 and directed by imperative needs. 



The secret of success in applied psychology 

 or human engineering is to be rigorously sci- 

 entific. On every occasion when the prin- 

 ciples of sound procedure were relaxed be- 

 cause of some real or fancied necessity, the 

 work suffered. The chief principles in much 

 of this personnel work concerned obtaining 

 data from the sources possessed of fullest and 

 most intimate knowledge, working only with 

 data of measured reliability, determining the 

 significance of facts by their proved conse- 

 quences and correlations, and verifying con- 

 clusions by a prophecy and experiment. When- 

 ever we made the extra effort and sacrifice 

 necessary to tap the best sources of informa- 

 tion about a man, rather than the next to the 

 best, there was a gain. When we took pains 

 to compute the reliability coefficients of all our 

 data before going further with them, we ^aved 

 time in the long run. Every failure to check 

 apparent meanings by objective correlations 

 was disastrous. An imverified hypothesis may 

 IKissibly be a relatively harmless luxury if all 

 one does with it is to think; to act on it is 

 a grave danger. 



Making psychology for business or industry 

 or the army is harder than making psychology 

 for other psychologists, and intrinsically re- 

 quires higher talents. The scientist doing 

 work for the inspection of other men of sci- 

 ence is in large measure free to choose his 

 topics, and to follow up any one important out- 

 come regardless of what task he originally 

 set himself. The scientist who is assigned a 

 problem and is without credit if, instead of its 

 answer, he produces something eventually far 

 more important, has to be more adaptable, 

 more persistent and more ingenious, if he is 

 to succeed equally often. It is relatively easy 

 to be scientific when you can direct your talent 

 in any one of ten thousand directions; your- 

 self asking the questions for which you pro- 

 ceed to find answers ! Psychology applied to 

 the complicated problems of personnel work 

 represents scientific research of the most 

 subtle, involved,, and laborious type. 



I have by intention omitted the names of 

 the psychologists who have shared in this work, 

 save where identification seemed necessary. 



