08 HELEN B. HUBBERT 



In an admirable discussion of the values of curves of learning 5 

 Miss Hicks says (p. 141): " The total distance criterion presents 

 so many difficulties as to render it impracticable for ordinary 

 work. One difficulty lies in the matter of taking records ac- 

 curately. The rats, after a few trials, run so rapidly that it is 

 extremely difficult for one person to observe and record at the 

 same time. To do this, it is necessary to mark off the maze 

 into small segments and commit to memory some scheme of 

 representation so that records can be jotted down in a purely 

 automatic manner. The work of transcribing this record into 

 distance terms and computing the same is very laborious. 

 Eliminating these practical difficulties, the distance criterion is 

 in some ways an ideal one. (Italics mine.) There can be no 

 divergence of practice as to what shall be omitted or included 

 and results obtained by different experiments upon the same 

 maze will be strictly comparable." (Page 154.) ' The distance 

 and error criteria are fundamentally alike. The distance curve 

 is the better representative of the progressive approximation of 

 the act towards automatic accuracy. It portrays all the details 

 of this eliminative process and it approximates the ideal of 

 uniformity and regularity of descent. However, it is impractic- 

 able from the standpoint of recording and manipulating the data." 



These practical difficulties in recording and manipulating the 

 data have been overcome, at least where small animals are the 

 subjects used in the maze. The total distance record can be 

 obtained accurately. Its desirability has, so far as we know, 

 never been questioned. The error curve has often been used in 

 lieu of the distance curve, but it has been criticized as practically 

 valueless because of the difficulties encountered in standardizing 

 an " error." 6 The prevalent practice of omitting all total and 

 partial returns from the error record, and of making no attempt 

 to evaluate varying degrees of error gives a curve which is not 

 only worthless but false." 7 



With this criticism on the customary methods of obtaining 

 the errors committed by an animal we are in hearty sympathy. 

 It is far better, both from the standpoint of convenience and that 



5 Hicks, V. C, The relative values of the different curves in learning. Jour. 

 Animal Befiav., Vol. 1, pp. 138-156. 



6 Watson J. B., The behavior of noddy and sooty terns. Carnegie Pub., No. 

 103, p. 249, note 1. 



7 Hicks. Ibid., p. 156. 



