Data Science, Machine Learning, Statistics, Open Source, Crossvalidation.
(predicting on unseen data). With fit our model with the first part and evaluate with the second part. Image by author. Here’s how to do it with code: Console output: (1/1): Accuracy: 0.91 We can see that the estimate is lower this time (0.91 vs. 0.97); the higher estimate is an overly optimistic