Bowley Skewness

Also known as Quartile Skewness Coefficient,

$${(Q_3-Q_2)-(Q_2-Q_1)\over Q_3-Q_1} = {Q_1-2Q_2+Q_3\over Q_3-Q_1},$$

where the $Q$s denote the Interquartile Ranges.

See also Skewness