194 ROBERT M. YERKES AND CHARLES A. COBURN 



On June 9th it seemed fitting to attempt a series of prelim- 

 inary trials. Each animal was given, in turn, opportunity to 

 secure food in each of the nine boxes. When the subject entered 

 the reaction space, B, the entrance door of a certain box stood 

 open, and as soon as the animal had entered that box, the ex- 

 perimenter closed the door behind it and opened the exit door 

 in front of it, thus enabling it to obtain food. During these 

 preliminary trials, the pigs were in separate yards and were 

 given their trials alternately. 



We shall now' report the results of our regular experiments. 



RESULTS OF EXPERIMENTS 



As it is essential to present the data for each trial in the series 

 of experiments, tables 1, 3, 4, 6, 7, 9, and 10 have been con- 

 structed after the following manner. At the head of each table 

 stand the several settings, the letter S serving as an abbreviation 

 for setting and the number following it designating the place of 

 the setting in the series. Immediately under the number of the 

 setting appear the numbers of the doors open with the one to 

 be chosen (correct one) printed in bold face type. Below this 

 preliminary information concerning the particular problem in 

 question, appear the results for each of the trials of each subject. 

 The column headed T gives the number of a trial in the total 

 series of trials for a given subject, in a given problem. Follow- 

 ing the number of the trial are the numbers of the boxes entered, 

 in the order of entrance. Referring to table 1, we discover that 

 the female in her first trial under problem 1 selected, of the 

 three boxes whose doors were open, first, number 3 She was, 

 of course, punished by being confined in this box for one minute, 

 and on release entered box 1, which was the correct box, and re- 

 ceived the reward of food. Or again, in table 3 it may be noted 

 that in trial 146, under problem 2, the female entered, in order, 

 boxes 7, 9, 7, and 8, the group of open doors including 7, 8, and 

 9, and the box to be entered being number 8. 



These tables will enable the reader to obtain quickly definite 

 information concerning the forms of response and the changes 

 therein during the course of experimentation. We shall present 

 the several tables under the problem numbers and reserve further 

 comment for the section on the discussion of results. 



