Statistics Definitions > Kelly’s Measure of Skewness
What is Kelly’s Measure of Skewness?
Kelly’s Measure Formula.
Kelley’s measure of skewness is given in terms of percentiles and deciles(D). Kelley’s absolute measure of skewness (Sk)is:
Sk=P90 + P10 – 2*P50 = D9 + D1-2*D5.
This formula is not practically used. In fact, Kelly’s measure of skewness is rarely used at all, even in its more common form, which is measured as coefficient of skewness:
SP = P90 – 2*P50 + P10 / P90 – P10
What does Kelly’s Measure of Skewness Tell us?
Kelly’s Measure of Skewness gives you the same information about skewness as the other three types of skewness measures (Bowley skewness, Pearson Mode Skewness and Momental Skewness.).
A measure of skewness = 0 means that the distribution is symmetrical.
A measure of skewness > 0 means a positive skewness.
A measure of skewness < means a negative skewness.