448 



Indiana University Studies 



abilities of the several grades. As in the case of the medians there 

 is great fluctuation from grade to grade and from process to proc- 

 ess within the several grades. At the left of the table there is 

 given a composite rank. As in the case of medians, city 13 ranks 



Frai9- VARIAEa[UTY SERIES B GRADE 5 MWrfPUCAHOn 



first and city 2 ranks last. Taking the entire group there is be- 

 tween the rankings in the two tables a positive correlation of 

 .794 figured by '^method of rank differences." Just why this cor- 

 relation should occur is not altog'ether clear. 



The per cent of variability of a class is a measure of the close- 

 ness of grading. Closeness of grading is essentially grouping to- 



