Yerkes and Dodson, Habit Formation. 



469 



acquired a perfect habit. On the twentieth day it was evident 

 that the stimulus was too weak to furnish an adequate motive 

 for the avoidance of the black box and the experiments were 

 discontinued. 



A few words in explanation of the tables are needed at this 

 point. In all of the tables of detailed results the method of arrange- 

 ment which is illustrated by table 3 was employed. At the top 

 of the table are the numbers of the mice which were trained under 



TABLE 3. 

 The results of the experiments of set I, stimulus weak ( 125 ± 10 units). 



the conditions of stimulation named in the heading of the table. 

 The first vertical column gives the series numbers, beginning with 

 the preference series A and B and continuing from i to the last 

 series demanded by the experiment. In additional columns 

 appear the number of errors made in each series often tests, day 

 by day, by the several subjects of the experiments; the average 

 number of errors made by the males in each series; the average 

 number of errors made by the females; and, finally, the general 



