Average absolute deviation

Average absolute deviation (also known as mean absolute deviation) is a way to measure how much numbers in a data set are spread out. To figure out the average absolute deviation you first have to find the average (or mean) of all the numbers in the data set. Then subtract each number from the average and take the absolute value of the difference. This is like taking away the "sign" of the difference. Finally add up all of the absolute values, then divide them by the number of numbers in the data set. This gives you the average absolute deviation. It tells you on average, how far each number is from the average of the data set.