1376 
number of mistakes, made by children of a certain age and the 
same sex, the average number of mistakes made during the minutes, 
by which the working-time of the group of children under con- 
sideration exceeded the minimum time required by a group of one 
and the same sex for the performance of the task. The same method 
was applied to the data of boys and girls taken together. Only, in 
this case we added to the average number of mistakes, made by 
children of a certain age, the average number of mistakes made by 
them in the minutes they worked longer than the children of the 
group that required the shortest time for the performance of the task. 
The values thus obtained are collected in 
TABLE lil. 
Age (years) Boys Girls Children 
8 61.4 62 61.7 
9 45 41.5 46.25 
10 39.5 40.6 40.05 
11 29.7 38.8 34.35 
12 22 29.6 25.8 
The quality and the quantity of the work achieved being in 
inverse proportion to the experimental value, it is evident from the 
table that boys work better than girls of the same age. At 8-, 9-, 
and 10 years the difference is not so great, but at 11-, and 12 years 
it manifests itself distinctly. The proficiency exhibited with the 
advance of years is best illustrated by a comparison of the experi- 
mental values for boys and girls together: from 8—12 years it 
amounts to as much as 58 °/). 
In Table IV we have given in the first column in percentages of 
the experimental values the superiority of the achievements of the 
boys over those of the girls of the same age. In the next three 
columns we have tabulated the progress made by the boys and 
girls together, and the two sexes separately, from 8—9, from 9—10, 
from 10—11, and from 11— 12 years. The increase of the achieve- 
ment with every transition is expressed in percentages of the experi- 
mental values. | 
When examining tables II] and LV more closely we see, that the 
achievements at 12 of boys and girls separately and of the two 
sexes collectively surpass those at 8 resp. 2.8, 2.2, and 2.4 times. 
