Skewness

Measure of the asymmetry of a distribution about its mean.

Also known as: g₁

Skewness quantifies the asymmetry of a distribution about its mean. It is the standardised third central moment.

Interpretation: g₁ ≈ 0 symmetric (e.g. normal distribution). g₁ > 0 right-skewed — the tail extends to the right (typical for waiting times, lifetimes). g₁ < 0 left-skewed — the tail extends to the left.

See also

Used in

In the Algorithm Lab

Sources

  • Joanes, D.N.; Gill, C.A.: Comparing measures of sample skewness and kurtosis, J. R. Statist. Soc. D, 47(1), 1998
  • Montgomery, D.C.: Introduction to Statistical Quality Control, 8th ed., Wiley, 2020