554 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



Pea, Pec, Tom, and Vea. The values for Kon, Spe, and Pre will be 

 given when they exist and may be compared, but are not included 

 in the group average. The average result for Squad B will be the 

 average of the individual records for the following 10 subjects: Pis, 

 Har, How, Ham, Lon, Liv, Sne, Tho, Van, and Wil. The individual 

 values, when available, will be given for McM, Kim, Mac, and Sch. It will 

 be of interest to note occasionally how far the fragmentary records of 

 the other subjects conform to the general findings for the group. 



Although the amount of time devoted to any one measurement on 

 an individual in an evening or morning session was rather limited, 

 the apparatus and procedure had been arranged with a view to taking 

 several observations of that particular kind, so that their average 

 would be a fairly good sample of the individual's performance in that 

 process or function. In illustration of this it will be seen as explained 

 in the section on program and technique (p. 137) that in the measure- 

 ments of the eye reactions, the word reactions, the eye movements, and 

 the electrical threshold, particular attention had been paid to this 

 matter. It was desired that the number of observations of a particular 

 kind on one subject should be large enough so that some statement 

 statistically significant regarding their consistency and uniformity 

 might be given. When practicable, the standard deviation and coeffi- 

 cient of variability^ for the individual subject and for each experiment 

 are included in the tables, and these individual variability measures are 

 averaged as are the other results. 



We are glad to take this opportunity of acknowledging the faithful 

 services of Miss Anna Berlin and Mr. Edward S. Mills in reading the 

 records and in many of the computations for the large amount of psy- 

 chological data. 



The date on which each neuro-muscular measurement was given for 

 the first time to the members of the two squads can be found in the 

 chronological record of the whole experiment (p. 60). It will be 

 further observed that for Squad B the first and second sessions (October 

 6 and November 3) and the third and fourth (November 17 and Decem- 

 ber 15) were in each case separated by 4 weeks. Between the fourth 

 and fifth sessions (December 15 and January 5) there was an interval of 

 3 weeks. The others were separated by 2 weeks or less. All of the 

 night observations were on Saturdays except those on January 13 and 

 27, which were on Sundays. January 5 was an unfavorable date experi- 



' The standard deviation was computed by the usual formula: — S.D. or a =a I In order 



to compare the variability in the results for one measurement with that in a series of observa- 

 tions of another process, it is desirable to know the relative size of the two variability measures 

 in terms of per cent of their respective averages or other central tendencj^ measures. In the 



S D # 



following tables the coefficient of variability, C =-^jj-: is employed, in which S.D. is the standard 



deviation and M the arithmetical average. (See Whipple, Manual of Mental and Physical Tests, 

 Part I, Baltimore, 1914, p. 24.) 



