THE ACQUISITION OF SKILL IN ARCHERY. 



113 



The scores of the two groups, this one record being omitted, are given in 

 table 36 and graphically in figure 14. If the averages of the first and last few 

 shots are taken as indices of the total improvement, there is a fairly large 

 dilTerence in the amount of improvement shown by the two groups. The 

 average, in inches from the bulls-eye, of the first and last 40 shots are given in 

 table 34. 



These averages make it appear that the laborers made the greatest absolute 

 improvement, while the investigators showed the greater initial and final skill. 

 From the appearance of the learning curves, it seems probable that the aver- 

 ages of the first and second halves of practice give the truer view of the skill 

 and improvement of the two groups. These averages are given in table 35. 



Table 36. — Average distance from bulls-eye of successive groups of 20 shots, for two unlike 

 groups of men under like conditions of practice with archery. 



Shots. 



4 I 3 iuves- 

 laborcrs.i tigators. 



Shots 



3 inves- 

 tigators. 



1 to 

 21 

 41 

 61 

 81 

 101 



241 to 160 

 261 280 



281 

 301 

 321 

 ,341 



300 

 320 

 340 

 360 



50.9 

 43.4 



44.7 

 38.7 

 48.8 

 44.8 



46.8 

 46.5 

 48.7 

 43.2 

 31.1 

 46.2 



From this it appears that there is no significant difference, cither in the' 

 absolute accuracy or amount of improvement shown by the two groups of men 

 shooting under the same conditions. 



DISTRIBUTION' OF PRACTICE AND RATE OF LEARNING. 

 PURPOSE AND METHOD OF THE EXPERIMENT. 



A year after the end of the experiment just described, with the completion 

 of the Baltimore range, the work was taken up again in a test of the effect of the 

 distribution of practice upon the rate of improvement. 26 subjects were 

 distributed in 4 groups, shooting daily 5, 20, 40, and 60 arrows respectively. 

 Owing to irregularity in attendance of some of the subjects, only 19 records 

 complete to more than 300 shots were obtained, and this fact accounts largely 

 for the differences in the nimiber of subjects and composition of the different 

 groups. 



The method employed in the experiments carried out in Baltimore was not 

 greatly different from that used in the Tortugas experiment. The subjects 

 were given only as much instruction as seemed necessary to prevent accident. 

 They were forbidden to discuss then- methods of shooting or to seek outside 

 instructions, and in his attempts to follow the various steps in the learning 

 process the experimenter avoided, as much as ]iossible, asking questions which 

 might give the subjects a clue to better methods of shooting. In one respect 

 the technique of the later experiment differed from that of the earlier. The 

 subjects were practically all volunteers and so interested in each other's shooting 

 that it was found impossible to prevent them from watchmg each other 

 practice. This gave a considerable opportunity foi' imitation, which was not 



