The mean absolute deviation,
or MAD,
of a data set is a number that measures variability, or how spread out the data values are. It shows, on average, how far each data point is from the Look at the below. The two data sets have different MADs. The first data set has a smaller mean absolute deviation than the second data set. So, the first data set varies less than the second data set. You can see how the data points in the first line plot are less spread out than the ones in the second plot.
