Question

What is the benefit of using mean deviation over standard deviation?

Answer 1

The benefits of using mean deviation over standard deviation are as follows :-

• Easy to interpret : Mean deviation is simply the average of the absolute differences between each score and the overall mean. However standard deviation is obtained by summing the squared values of the deviation of each observation from the mean, dividing by the total number of observations, and then taking the positive square root of the result.
• Error propagation : If the observations are in error, the mean deviation measure can allow for cancellation of the total error present in the final measure but in s.d the total error would be added as a squared term for every observation. Thus in the presence of errors mean deviation provide much reliable information than standard deviation.
• For non-normal distribution : For observations from other than a normal family the standard deviation is a less reliable measure of dispersion than mean deviation.