Question

how to find the goodness of fit in regression

Answer 1

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1. You can use R2R2 to examine how well your model fits the training data. This will tell you what percentage of the variance in the data are explained by the model.

2. I suggest using RMSE (root mean square error) of your predictions on your test set when compared to the actual value. This is a standard method of reporting prediction error of a continuous variable.

3. Another method that you can use is to cross-validate regression models to see how well they generalize to new data. The metric of choice is mean absolute error on the cross-validated data, but root mean squared error is more common and equally useful.