Pour general categories were set up: (a) Memoranda, which were 

 the results of short studies usually in response to specific 

 requests and ordinarily were distributed only to bhe person or 

 persons making the request: (b) Studies, which were reports on 

 research involving more than one or twc mar lay's of work, and 

 hich normally had only a limited circulation outside the group; 

 (c) ORG reports or publications, which s t that when a study 

 received widespread appr 1 from t"' e jroup and when ;sts 

 for it resulted in a fairly wides read iistributlon, after 

 editing ar ; ■ 1, it was reissued as an ORG report or pn - 

 lication; (d) Contributions, which were portions of studies 

 which sc t i . :■ appeared in '' fc rra of articles in seme of- 

 ficial Kaval publication. 



Punch Cards . 



Analyses, madi ■ ssible through the use of punch cards 

 and IBM machines we?>* most helpful in measuring the efficiency 

 of tactics and of ?. Eastern Sea Frontier provided iany of 

 the data which went onto the punch cards. Each plane on re- 

 turning from an anti-submarine patrol filled out a form which 

 gave the details of the mission and the details of any sight- 

 ings, visibility, and so on. 



In the securing and t] e analysis of data from anti- 

 submarine action reports and the preparation of situation 

 submarines, the members of Group M came to depend upon Com- 

 mander (new Captain) R. F. Collins. Eis understandj 

 cooperation saved '- 1 i p from tany false starts. In the 

 devising of punch; carls and the 3 : ning of codes certain 

 Members of the group played important parts. Among these 

 were Professor Wilks and Messrs. W. L. DeVries, PL H. Henning- 

 ton, P. J. McCarthy and later Mr. R. R, Seeber, find Mr. Earl" 

 Gardner, 



As the work of >roup M ssed, the card files grew. 

 In addition to the ships' casualty files cf the world-wide 

 assessment files, there were files giving details concerning 

 attacks en enemy s bma -Ines by U. S. surface and aircraft 

 and on convoys. Another file was bi sed on action reports of 

 our own arines in the Pacific and another on air actions 

 in the pacific. 



Determination of the probability of success in depth- 

 charge patterns led tc the punching cf 7,500 cards giving 

 error distribution based on operational statistics covering 



