58 



SCIENCE 



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



chantman. He solved this by moving the imi- 

 tation target through an 84-phase series of 

 combined sine curves at variable speeds by a 

 simple set of eccentrics, motor-run. He had 

 the problem of imitating the essentials of the 

 control of the gun by the gun-pointer and of 

 recording in a fuller and more convenient form 

 the exact nature of the gunner's reactions in 

 picking up the target, in getting on the bulls- 

 eye, in keeping on, in firing when he was on, 

 and in following through. He solved these by 

 a simple graphic record showing all these re- 

 actions on a single line that could be accurately 

 measured, or roughly estimated. 



Subsequently he made an apparatus that 

 could be used not only to test a prospective 

 gun-pointer's a;bility, but also to train both 

 gun-trainers and firing gun-pointers four at 

 a time. The demand for these instruments 

 has been so great that sixty have been built by 

 the ISTavy for use at shore training stations. 

 The success of this led to further similar work, 

 especially on the problem of the listener, the 

 lookout and the fire control party. 



The selection of military aviators is inter- 

 esting as showing the complexity of a single 

 concrete personnel problem. To be a success- 

 ful military aviator in the United States Army 

 under the conditions of the great war required 

 first, that the individual be able to complete a 

 theoretical and practical course on the ground 

 (in a School of Military Aeronautics) ; second, 

 that he be able to learn to fly satisfactorily 

 within la reasonable time in an Aviation School 

 or " Flying School " ; third, that he possess 

 the mental and moral make-up qualifying him 

 for a commission in the army; fourth, that he 

 prove competent in actual military work " over 

 the lines" as pursuit pilot, bombing pilot, or 

 pilot carrying an observer, or as a pilot in- 

 structor. 



If we had perfectly accurate measures of 

 a hundred thousand men available for the four 

 traits: (1) 'ability in the ground school; (2) 

 ability in the primary training in the funda- 

 mentals of flying; (3) standing in the com- 

 posite of manhood and devotion characteristic 

 of the ideal commissioned officer; (4) fitness 

 for the actual work of a military aviator at the 



front; we should still have a complex problem. 

 For these four abilities are very imperfectly 

 correlated. The correlation of (1) and (2) is 

 ajpparently not over .3. The correlation of 

 (1) and (3) is probably not over .5. That of 

 (1) and (4) is almost certainly not over .4. 

 That of (2) and (3) may be as low as .3. That 

 of (2) and (4) and that of (3) and (4) are 

 not known, but it is certain that neither is 

 very near 1.00. 



Consequently, even if perfect prophecies 

 could be made in respect to a man's fitness for 

 each of the four requirements, the use of them 

 to give the maximum of satisfaction of (3) 

 and (4) (general officer quality and actual suc- 

 cess as a military aviator) with the minimum 

 of waste of time and money in respect to (1) 

 and (2) is a problem demanding careful analy- 

 sis. 



A far greater difficulty of course was to dis- 

 cover means of prophesying abilities in a 

 school such as had never before existed, in an 

 art which only a few score men in the country 

 had learned, and in a form of ;warfare which 

 was only three years old and was changing its 

 nature radically every few months. 



Progress was necessarily slow and piecemeal, 

 and anything like a complete and precise bill 

 of specifications of the successful military 

 aviator in terms of traits observable in a young 

 man at work and at play on the ground is still 

 remote. 



Some of the steps in the progress may serve 

 to illustrate further the analytic side of per- 

 sonnel work. In a study of the qualities used 

 by examining boards to select future aviators, 

 it was apparent that amount of ischooling was 

 the closest symptom of success in the work of 

 the ground' school. An experimental investi- 

 gation was then undertaken to decide whether 

 the score in a systematic test of intelligence or 

 mental alertness might not be a useful addi- 

 tion to the scores for amount of schooling. 

 Such a test was devised which gave a better 

 prophecy of success in the ground school than 

 amount of schooling, the correlations being, re- 

 spectively, about .60 and .26. Application of 

 the partial correlation technique showed that 

 the test score was the primary factor, amount 



