R Squared is the coefficient of determination it normally ranges from 0 to 1, and provides a measure of how well observed outcomes, are replicated by the model.
The formula is:
Residual(Error) sum of squares (RSS), also known as (SSR) , is the sum of the squares of the deviations predicted from actual empirical values of data.
It is a measure of the discrepancy between the data and an estimation model.
Total sum of squares (TSS) is defined as being the sum, over all observations, of the squared differences of each observation from the overall mean.
Basically, this means the measurement of accuracy for the model by comparing the prediction errors from the specific actual values and a baseline of the predictions from the average of the actual values.
