462 H. M. JOHNSON 



Dunlap, for use with the Burroughs adding machine in studies 

 of habit-formation. This material had been derived by subject- 

 ing a constant to a certain systematic treatment which insured 

 an even distribution of difficulties among the several sets of 

 material, and minimized and regulated the occurrence of repeti- 

 tions. The amount of this material available was too small for 

 our purposes. Several weeks were therefore spent in the com- 

 pilation of additional material according to a key furnished by 

 Professor Dunlap, and a fair amount of satisfactory material 

 was thus obtained. 



A lighting booth was then constructed; various types of distri- 

 bution of illumination were procured, and an adding machine 

 installed. As the machine is large, and under the conditions of 

 operation fills a large part of the visual field with surfaces of 

 varying types and degrees of reflectivity some being black, 

 others nickelled, and most of them highly polished it was neces- 

 sary to screen the machine from view of the subject, and require 

 him to learn to operate it by the "touch* 1 method. 



Six subjects were employed, five being undergraduate students 

 in the college for women of Western Reserve University. The 

 college is located several miles from the laboratory, and it proved 

 impossible to maintain a regular or satisfactory schedule. It 

 became evident after some weeks that the subjects would not 

 master the "touch" system of operation in time to complete the 

 preliminary experiment according to plan within the academic 

 year. The diurnal variations in performance under a single 

 lighting condition were too great to justify the expectation that 

 the various lighting conditions would show differential effects, 

 unless the lighting conditions under comparison were extreme, 

 unless an enormous amount of work material was provided and 

 used, or unless the preliminary training period was to be indefi- 

 nitely prolonged. It was therefore decided to abandon the 

 experiment in favor of a method which involved a less intricate 

 muscular coordination, until more favorable conditions for the 

 use of the "simpler" method could be obtained. The work 

 method under fair conditions of operation may be valuable. 



