58 THOMAS WILLIAM BROCKBANK 



of learning fall very close together, but it seems that the 

 method of wider distribution is the most economical. A 

 similar situation developed in redintegration but the 

 averages, if any conclusion may be drawn from them, 

 show that the three trials per day group is superior. From 

 these tables it must be admitted that the results of these 

 two groups are inconclusive in regard to the question of 

 economy. Because the averages of time and trials are so 

 nearly equal it may be said that on the whole neither the 

 three trials per day method nor the one trial per day method 

 has any decided advantage in point of time and trials. 



The data from observation indicate a greater number 

 of movements, such as in the attempt to push down the 

 plane, due to the three trials per day methods, and this 

 fact may be interpreted to indicate a greater economy of 

 the wider distribution of trials. Because of the persistance 

 of the dominant " error," the inclined plane presents one 

 of the most difficult problems with which to carry on any 

 satisfactory and consistent experiments. In any case, a 

 larger group of rats should be experimented with before 

 one can be certain of anything definite; and, certainly, as 

 far as economy is concerned in redintegration, the problem 

 must be approached on a broader scale than the one here 

 presented before there may be any hope of a conclusive 

 result. 



In order to ascertain the effect of retention on incomplete 

 learning, two litters of rats were set to learn the inclined 

 plane by the one trial per day method. The results of 

 this experiment are presented in Table XIII. In this ex- 

 periment the usual norm was adhered to, except that each 

 litter was taken from the problem when the first rat of 

 the respective litter finished both in learning and redin- 

 tegration. Under similar conditions on the maze it was 

 seen that the rat which completed learning first did not 

 complete redintegration first. The present table shows that 

 the result on the inclined plane follows that on the maze 

 in this respect. 



Probable explanations of this fact, as already stated in 

 the consideration of incomplete learning on the maze, are 

 as follows: That the rat which finished first in learning 



