A central measure that is the mid-point at which precisely half the values are below and half above. It is typically more {{robust} than the arithmetic mean (μ), but the latter is easier for certain kinds of calculation. The term average most commonly refers to the arithmetic mean (μ), but can also refer to the median, especially for asymmetric distributions, where the median is typically a little smaller than the mean (μ), because the latter can be influenced by a few large outliers. For example, 'average income' usually refers to the median, not the mean (μ).