In Mean Square Error?

In statistics, the mean squared error (MSE) or mean squared deviation (MSD) of an estimator (of a procedure for estimating an unobserved quantity) measures the average of the squares of the errors—that is, the average squared difference between the estimated values and the actual value.

What does mean squared error tell us?

The mean squared error (MSE) tells you how close a regression line is to a set of points. It does this by taking the distances from the points to the regression line (these distances are the “errors”) and squaring them. The squaring is necessary to remove any negative signs. ... The lower the MSE, the better the forecast.

How do you calculate MSE?

To calculate MSE, you first square each variation value, which eliminates the minus signs and yields 0.5625, 0.4225, 0.0625, 0.0625 and 0.25. Summing these values gives 1.36 and dividing by the number of measurements minus 2, which is 3, yields the MSE, which turns out to be 0.45.