Describe three popular measures of forecast accuracy

What will be an ideal response?

Measures of forecast accuracy include: (a) MAD (mean absolute deviation) is a sum of the absolute values of individual errors divided by the number of periods of data; (b) MSE (mean squared error) is the average of the squared differences between the forecast and observed values; and (c) MAPE (mean absolute percent error) is the average of the absolute differences between the forecast and actual values, expressed as a percent of actual values.