Measure of central tendency

variance is a natural measure of central tendancy, but there are others.

qthq^{th} central moment: 𝔼[(X𝔼X)q]\mathbb{E}[(X-\mathbb{E}X)^q]

q=2q=2 gives the variance


In proof of Hoeffding Inequality:

Idea in brief: Apply Markov’s Inequality to 𝔼[(X𝔼X)q]\mathbb{E}[(X − \mathbb{E}X)^q] for larger q, or more generally to f(X𝔼X)f(X − \mathbb{E}X) for some other non-negative function ff. E.g., to exp(XEX)\exp(X − EX).


References:

  1. CS6763 Lecture 3, page 14