# Definition of Sum of Squares

Measure of variation or deviation from the mean is known as the sum of squares. It is calculated as a summation of the squares of the differences from the mean. The calculation of the total sum of squares considers both the sum of squares from the factors and from randomness or error.

## Explanation of Sum of Squares

Sum of squares is a statistical technique used in regression analysis. In order to know the dispersion of data points, the sum of squares approach is used. The main goal in regression analysis is to determine how well a data series can be fitted to a function which might help to explain how the data series was generated. The sum of squares is used as a mathematical way to find the function which best fits (varies least) from the data.