The recently introduced distance standard deviation plays similar role to the mean difference but the distance standard deviation works with centered distances.

They come from testing for no mean difference, and thus are not designed to measure the size of compound effects.

Both the standard deviation and the mean difference measure dispersionhow spread out are the values of a population or the probabilities of a distribution.

If a random variable has a positive mean, then its relative mean difference will always be greater than or equal to zero.

The survival of lice in most of these transfers was significantly reduced in proportion to the mean difference in feather barb size between the donor and recipient species of hosts.