The Average Absolute Deviation or Mean Absolute Deviation is a simple measure of dispersion that takes the mean of the absolute deviations from a central point. In general any central point, such as the mean, median or mode can be used. However, for this calculation only the mean will be used. In other words, the absolute values of the differences between the data points and the mean of the data points will be totaled and then the sum will be divided by the number of data points.