Most commonly used metrics for Linear Regression Model Imagine a Class with Test Score, s uppose you are in a class and your teacher gives you and your friends a test. Following the test, your teacher wants to know how good the class actually did. To do so, she tries to predict how well everybody would perform based on the study time. Then, following the test, the teacher compares the predicted scores to the actual scores that you all attained. The teacher wants to know how far off the predictions were from the real scores. This is where MSE, RMSE, and MAE come in, they are ways of measuring the errors or mistakes between predicted scores and real scores. 1. MSE (Mean Squared Error) Suppose your teacher predicted that you would score 90 on the test, but you actually scored 80. The error here is: 90 - 80 = 10 Now, we square it instead of using the error itself. That means, multiply the error by itself. So: 10 * 10 = 100 Why square it? The reason is because squaring makes s...