PSYCHOLOGICAL PROGRAM AND TECHNIQUE. 145 



stances they would note that the horizontal columns were unchanging 

 and would try to memorize them.^ 



Immediately at the close of the 10-minute period of addition, the 

 blank was turned face down on the table in front of the subject, in the 

 same position as before the signal was given to begin the test. The 

 subject then took out his watch, laid it on the table, and made a pulse 

 count on himself for a period of 30 seconds. He recorded this count on 

 the back of the addition blank, under the date with his name.^ 



(3) Discrimination for Specified Number Groups on a Printed Page. 



The addition blank served as the material for this test also. Each 

 column of 10 digits was regarded as a unit, as if it were the only material 

 on the page. Each and every combination of two successive numbers 

 which, when added together, equaled 11, were to be canceled by drawing 

 a line through them connecting the two.^ Thus the combinations 

 found would be: 2 and 9; 3 and 8; 4 and 7; 5 and 6; and the same in 

 their reverse order. A group of numbers, such as 4, 7, 4, would be 

 regarded as two such combinations and a line drawn through, 

 connecting the three digits. Figure 20 shows a portion of a num- 

 ber cancellation record. The frequency of combinations of two suc- 

 cessive digits equaling 11 is of course not the same in all blocks of 

 digits, but as the 5-niinute interval allowed for this test was sufficient 

 for most of the subjects to cover several blocks of the material, this 

 factor was neglected. The subjects were instructed to go over all the 

 horizontal lines of the 8 blocks of material on the blank and to check 

 each one of the desired combinations. Then the vertical columns were 

 checked, beginning as before at the upper left-hand corner. Previous 

 to each trial it was impressed upon the subjects that they must mark 

 every combination equaling 11 and that they would be penalized for 

 leaving unmarked any such combination in the material which they 

 had gone over. Immediately at the end of the 5-minute interval 

 allowed for this task, the blanks were taken up. In scoring the record 

 the last combination mark was considered the limit of the material 

 which they had covered. 



(2) Discrimination for the Pitch of Tones. 



Pitch discrimination is a measurement which can be easily given by 

 the group method. A well-recognized standard form of procedure has 



^ This possible difficulty could have easily been provided against, as the linotype slugs could 

 have been cut, making them just half as long. Each slug would then have contained 5 digits and 

 the number of possibilities for combinations into columns of 10 would have been almost infinite. 

 This method will be followed in any subsequent printing from these same slugs. 



^ Several of the subjects in Squad A found considerable satisfaction in chewing gum. (See 

 p. 266.) They were asked to remove the gum from the mouth during the addition test. 



3 It was first suggested to us by Professor H. S. Langfeld that we use the cancellation test in 

 somewhat this form. Langfeld and Allport, An Elementary Laboratory Course in Psychology, 

 Boston, 1916, p. 100. See also Burtt, Journ. Applied Psychol., 1917, 1, p. 201. 



