8 



Indiana University Studies 



Causes of Variability in Scores 



There are but two possible causes for the variabUity of scores. 

 One is the variabiUty in original endowment of children. The 

 other is the effectiveness of environmental conditions on the 

 growth and development of children. If we should accept the 

 first hypothesis as an adequate explanation of the variability 

 found in these scores we must argue that in those schools with 

 low scores we have children of less than average ability and that 

 other cities attain high scores because their children are unusually 

 gifted. Two things are against such an explanation. First, there 

 is no conclusive evidence from the experimental studies of in- 

 dividual differences that such widely separated types of individuals 

 are to be found among such fairly homogeneous populations as 

 live in these Indiana cities. The second obstacle to such a theory 

 is that you get widely different results within the same cities 

 and within the same school. Thus city 2 scores 6.5 in the eighth 

 grade addition and but 1.5 in the fifth; city 4 is 40 per cent above 

 the median in sixth grade addition and 14 per cent below the 

 median in multiplication in the same grade. Such facts as these 

 do not indicate differences of mental endowment on the part of 

 the children. They rather indicate ill-adapted environmental 

 conditions. These environmental conditions may be divided into 

 two groups, the school and the non-school. The latter comprise 

 such facts as conditions of family life, feeding, recreation, and 

 outside work. Of the great importance of such factors as bearing 

 upon school work there can be no doubt. There is, however, no 

 reason to believe that such conditions are peculiar to any city 

 in a manner adequately to account for the variability of scores. 

 In fact, some cities and individual schools in the poorer sections 

 of other cities show approximately as good work as do the better- 

 cared-for children in the more favored localities. 



With these possible explanations eliminated we must recur 

 to the differences in the school conditions to account for the 

 differences in the scores. Where one city scores higher than 

 another, the difference is probably due to the fact that the school 

 conditions in the one city are superior to those of the city with the 

 lower score. When city 20 scores 100 per cent in dependability 

 in division in three grades it means that the administrative and 

 teaching force in that city have learned how to teach division 

 effectively, and when city 7 makes but 58 per cent in eighth 

 grade addition, while scoring much higher in the other processes, 



