Machine Learning Fundamentals › Training vs Testing Data
What are common mistakes to avoid with Training vs Testing Data
IntermediateAnswer
A common mistake is letting information from the test set leak into training, for example by scaling the entire dataset together before splitting, which gives falsely optimistic results.
Real-world example A bank builds a loan approval model on data from the last five years and tests it on the most recent six months of applications to see how it would have performed in practice.