CHAPTER VIII 



Problem Learning 



1. Analysis of the problem 



The problem which the chick is expected to solve in the experi- 

 ments that have been described in the preceding chapters may be 

 regarded, for present purposes as divided into two separate tasks. 

 The first task, learning the experiment box, is really a maze prob- 

 lem. The experiment box with its entrance box, discrimination 

 chamber, electric compartments, exits, and nest boxes — is only 

 one of various types of maze. The types of maze, commonly re- 

 garded as such, provide, more or less frequently, choices be- 

 tween open and blind passage ways. These open or closed 

 passages are also present in the experiment box, but the two 

 courses are permanent in the maze proper whereas the corre- 

 sponding courses in the experiment box are interchangeable. 



The principle of interchanging the open and closed passages of 

 the experiment box demands the simultaneous display of two dif- 

 ferent stimuli, one signifying ''this way out" and the other "exit 

 closed." With the introduction of these two differentiating stim- 

 uli, there appears for the animal the second task of "interpreting 

 the signs." Before the experimenter can study the animal's 

 ability to interpret these signs — the power of distinguishing, for 

 example, a 5 cm. square from a 3 cm. square or a circle from a tri- 

 angle — it is necessary that the animal should have learned the 

 principle of the experiment box or maze problem. The solution 

 of this maze problem provides opportunity for noting the animal's 

 method of forming habits. 



As a matter of economy, the experimenter naturally presents the 

 signs of "exit" and "closed" in appropriate relation to the course 

 which the animal is required to follow in learning the initial maze task. 

 The positive ( + ) sign meaning "exit" is displayed at the begin- 

 ning of the training series in significant connection with the course 

 prescribed for the animal to reach the nest box. Similarly, the 

 negative ( — ) sign meaning "closed" appears contiguously with the 

 forbidden nest box. With the exception of two preliminary or 



