"be properly regulated. This was found to be a very 

 important thing throughout learning, and especially was 

 this true in the early trials when learning is laborious 

 and there is a change in the amount as well as in the 

 periodicy of feeding. 



The experiments show that a trial given every two 

 days, is more economical than more frequent trials, that 

 is, when the number of trials is distributed over several 

 days the total time required for learning is the shortest. 



Again one trial given daily with either one problem 

 or several in succession, is decidedly more economical 

 than when several are given daily. And it is better to 

 give one problem at a time than several at a time. 



When several trials are given daily with one or more 

 problems fewer days are required to learn either one or 

 several problems. 



From the above, when considering the total time 

 and energy consumed, learning distributed over several 



