Semivariance

For the measure of downside risk, see Variance#Semivariance

In spatial statistics, the empirical semivariance is described by

where z is a datum at a particular location, h is the distance between ordered data, and n(h) is the number of paired data at a distance of h. The semivariance is half the variance of the increments , but the whole variance of z-values at given separation distance h (Bachmaier and Backes, 2008).