A COEFFICIENT OF VARIABILITY

A coefficient of variability is described. It is shown that conducting all possible paired comparisons in a group of scores, the investigator can ascertain the group’s degree of variability as well as its converse, the group’s degree of homogeneity. The coefficient, useful in determining whether to divide a class into subgroups for the purpose of instruction, has the advantage that it is in the form of a proportion and that it thus provides a common ground for comparison of variability across measures.