122 



THE ACQUISITION OF SKILL IN ARCHERY. 



what different way indicates that there is probably a fairly close correlation 

 between distribution of practice and rate of improvement when chance causes 

 of variation in the records can be eliminated. 



During the first part of practice improvement is made largely by a series of 

 what Thorndike has called "insights," such as those found so constantly by 

 Ruger in the solution of mechanical puzzles. The sight and feel of the bow, 

 arrow, and target present certain elements in common with the stimuli which 

 call out many habits of manipulation and habits dealing with space relations 

 and so tend to call out the same movements. Thus habits of aiming with the 

 rifle are transferred to sighting along the arrow and need little modification 

 to become efficient in producing accurate shooting with the bow. Such 

 coordinations of complex preexisting habits occur early in the practice of every 

 subject, but whether they come before a single shot is fired, at the fifth shot, 

 or at the sixtieth shot is largely a matter of chance. The subject whose record 

 is shown in figure 17 had opportunity to see the practice of the 5-shot group for 

 two weeks before his own practice was begun, with the result that many of the 

 simpler problems of aiming were worked out in terms of the speech mechanism 

 before he loosed a single shot. The result was somewhat the same as learning 

 with instruction, as shown in figure 13. 



TABLE 40. Improvement in accuracy after 360 shots ivith the bow. 

 [Averages are in inches from the center of the bulls-eye.] 



These factors result in a greater variability in the earlier part of practice 

 than in later practice, which is independent of the distribution of practice, 

 for few large groups of habits are added after the first 100 shots, as is evidenced 

 by the fact that in later practice the subjects can rarely tell to what changes in 

 their method of shooting their improvement is due, while in the early stages 

 of practice such exclamations as "Oh, I've caught on to something," are fre- 

 quently followed by sudden large increases in accuracy. 



The elimination of the first trials, then, probably gives a truer picture of 

 the effect of the distribution of practice than the inclusion of the earlier prac- 

 tice period. The averages of the first, second, and last third of practice have 

 been computed for each group and are given in table 4 1 . 



