PSYCHOLOGICAL MEASUREMENTS. 575 



viduaFs record from experiment to experiment, yet in general this is 

 not such as to make it apparent that one individual influences pre- 

 dominantly the average for any one date. Five of the subjects 

 whose records enter into the final averages for the squad, that is, 

 Can, Gul, Moy, Pec, and Vea, have average low-diet errors of 19 per 

 cent or above. Not one of these 5 subjects on any of the 9 dates 

 which fell within the reduction period has a percentage of error less 

 than 10 per cent. The largest is for Pec on October 13, viz, 40.7 per 

 cent. This is somewhat compensated in the average by the fact that 

 Moy on the same date had 26.1 per cent, which was a little below the 

 average for him during the first part of the experiment. The errors 

 for Gul were large, but during the greater part of the experiment they 

 were quite consistent. Beginning with September 29 they are, in 

 order, 25.0, 22.4, 24.5, 25.0, 18.3, 21.0, 23.8, 21.2, 12.3, and 12.7 per 

 cent. The average score for Squad A during the whole of the reduc- 

 tion period, as shown at the bottom of the right-hand column in table 

 155, is 45.1 columns correct, mth 15.5 per cent of errors. 



In the case of Squad B the normal average performance shows that 

 the individuals who made up this squad demonstrated a larger average 

 variability than was found in Squad A. The scores for columns cor- 

 rectly added range from 85.8 and 68.8 for Tho and How, respectively, 

 to 14.8 and 9.0 for McM and Sch. The data for the last two sub- 

 jects are only fragmentary, as was also the case with Spe of Squad A. 

 Nevertheless, there is somewhat more variability in Squad B, since 

 no one in Squad A did so well as Tho and How of the former, and more- 

 over, the scores of Har and Ham (22.6 and 23.0), both of Squad B, 

 are slightly smaller than the smallest score with Squad A, i. e., Can, 

 25.3.^ The average normal performance for Squad B is 41.9 correct 

 columns — about 3 columns less than the low-diet average of Squad A. 



In the matter of percentage of errors, with the exception of Sch 

 and McM, whose data, particularly those of the former, have been 

 mentioned as incomplete and do not enter into the average for Squad 

 B, the values are in general in the same range as those found for 

 Squad A. The final normal average of 11.8 per cent for Squad B is 

 3.7 per cent less than that found for Squad A. It is noteworthy that 

 the two subjects of Squad B, who lead with the largest number of 

 columns correctly added, are also in the lead in the smallest percentage 

 of errors of any of the 10 subjects from whom the final squad average 

 is drawn. In comparing Squad B's normal average with the average 

 for the three reduced-diet dates, only minor fluctuations are noted. 

 Seven of the 10 subjects show increase in the number of columns 

 correctly added. Only 4 showed a reduction in the percentage of 

 errors. The final average for this period shows an increase of 2 

 columns in the 10 minutes, i. e., 43.9 compared to 41.9, and a decrease 

 of 0.7 per cent in errors, 11.8 to 11.1 per cent. 



^This comparison is among the 10 regular subjects of each squad. 



