Description: Mean absolute deviation (MAD) of a data set is the average distance between each data value and the mean. Mean absolute deviation is a way to describe variation in a data set. Mean absolute deviation helps us get a sense of how "spread out" the values in a data set are. Let's say that I've got two different data sets. "Is there a number that can give me "a measure of center of each of these data sets?" And one of the ways that we know how to do that is by finding the mean.*Teacher Advisor is 100% free.