82 



Indiana University Studies 



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65 



6A 



7b 



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6A 



Fig. 1. Scores in Attempts, Rights, and Dependability in Addition 

 FOR Both February and June. 



The score on the ordinate indicates the number of problems; the 

 symbols along the abscissa indicate the successive grades from 6B to 8A. 



Together with the gain in median scores from February to 

 June, we must consider the change in variability. If this gain has 

 been accompanied by an increased per cent of variabihty its value 

 is questionable. Table IV shows what happened. In attempts 

 the variabihty in grades 6B and 7A shows no change. In grades 

 6A, 7B, and 8A there is less variabihty. In 8B there is a shghtly 

 greater variabihty. But note what happened in dependabihty. 



