Chapter 9 – Testing and Debugging for Production
- Data drift: Data drift happens if the characteristics and meaning of features or independent variables in production differ from the modeling stage. Imagine you used a third-party tool to generate a score for the health or financial situation of people. The algorithm behind that tool could change over time, and its range and meaning will not be the same when your model gets used in production. If you have not updated your model accordingly, then your model will not work as expected as the meaning of the value of the features will not be the same between the data used for training and the user data after deployment.
Concept drift: Concept drift is about any change in the definition of output variables. For example, real decision boundaries between training data and production could be different because of concept drift, meaning the effort in training might result in a decision boundary far from reality in production...