358 H - M JOHNSON 



a way that as the subject gazed through the frosted lenses at 

 the wall the entire visual field appeared as of nearly a uniform 

 brightness of approximately 15 candles per square meter (vary- 

 ing somewhat if the position of the head were considerably 

 changed) and having a distribution of energy among the wave- 

 lengths of the visible spectrum approximating that of a black 

 body at 2600 K. Hereafter the first condition will be called D 

 and the second condition, L. 



At each sitting the subject was required to sort the shuffled 

 pack four times: twice under each condition. Two orders of 

 presentation were used in alternation : (a) LDDL and (b) DLLD. 

 Hah* the subjects were given order (a) at the first sitting and the 

 other half order (b). No consistent effects on the averages were 

 discoverable. 



The subject was informed that his performance would be 

 rated on both speed and accuracy; that he would be penalized 

 for mistakes sufficiently to overbalance any gain in speed which 

 he might make at the expense of accuracy. He was instructed, 

 however, not to expend time in correcting a mistake once made, 

 as this would tend to double the penalty. He was also advised 

 to try for accuracy at the expense of speed until perfect accuracy 

 was attained, and was assured that the early acquisition of ac- 

 curacy would tend to make for earlier and more rapid acquisition 

 of speed. He was instructed as to the purpose of the experi- 

 ment, but was informed that no reason existed for expect ing a 

 differential effect in favor of either condition; and he was urged to 

 try equally hard for a maximum of achievement under both 

 conditions. 



THE SUBJECTS USED 



Some information regarding the 16 subjects may be of interest. 



E. S. and G. H. were laboratory technical assistants, graduated 

 from high school some two years previously. F. G. was the lab- 

 oratory electrician. These three subjects were somewhat handi- 

 capped with respect to the others, by reason of calloused finger- 

 tips* 



