RMSE(root-mean-squared error)

RMSE(root-mean-squared error)

It does this by measuring difference between predicted values and the actual values.

In a good model, the RMSE should be close for both your testing data and your training data.

출처: https://www.quora.com/What-is-the-meaning-of-root-mean-squared-error-RMSE-in-statistics