PSYCHOLOGICAL MEASUREMENTS. 



561 



those with A. It is, furthermore, unfortunate that the last normal 

 date for this squad (January 5) was the immediate close of the vaca- 

 tion period and was separated from their previous experiment by 3 

 weeks. The conditions in the two observations preceding the food 

 reduction with Squad B are not favorable for reveahng the influence 

 of the 3 weeks of reduced diet. Notwithstanding this, it is evident 

 from the curve in figure 102 that up to the sixth experiment, in spite 

 of the longer intervals between experunents, Squad B shows a superior 

 performance to Squad A. At the sixth experiment, the first in the 

 reduced-diet period for Squad B, they are slightly poorer than Squad A, 

 and in their next two, January 19 and 27, while they improve over 

 January 13, 

 they do not 

 reach the rec- 

 ord of Squad 

 A for January 

 26 and Febru- 

 ary 2, which, 

 considering 

 their superi- 

 ority over 

 Squad A in 

 experiments 2 

 to 5 inclusive, 

 they might 

 reasonably 

 have been 

 expected to 

 reach. 



It seems 



justifiable to conclude, although the results for Squad B, unless inter- 

 preted in the light of certain modifying conditions, will not entirely 

 support the statement, that with Squad A, particularly during the 

 months of October and November, the motor functions involved in 

 steadiness in tracing as used in this test were interfered with by the 

 reduced diet, since the squad as a whole did not do such accurate work 

 or make such rapid improvement in the test as would have been 

 expected of them under normal conditions. 



(2) DISCRIMINATION FOR THE PITCH OF TONES. 



Seashore and his collaborators^ have concluded as a result of a 

 great deal of experimentation that the ability to discriminate the pitch 

 of tones is elemental and the sensitiv eness of the ear to pitch dif- 



» Seashore, Psychological Monographs, 1910, 13, p. 53; Smith, F. O. (Iowa Studies in Psychology, 

 6), Psychological Monographs, 1914, 16, pp. 67 to 103, particularly p. 101 ; Seashore and Mount 

 (Iowa Studies in Psychology, 7), Psychological Monographs, 1918, 15, pp. 47 to 92; also. Seashore 

 and Tan, ibid., pp. 159 to 163. 



Fig. 102. — Errors in accuracy of tracing between parallel lines. 



