Range-to-variance ratio

The range-to-variance ratio measures how well a fitted regression model might predict new values. It is defined as the range of estimated values at the original data points, divided by the average variance of the estimated values. It measures the variation of predicted values due to the model, versus the variation due to uncertainty in the model. A high value, greater than 10 for example, indicates that the prediction is likely worthwhile. A low value, less than 4 for example, suggests that the uncertainty in the model is high enough that predicted changes may not be significant.