A production dataset may contain many fields that are irrelevant, redundant or unavailable at the intended decision time. Feature selection makes those input choices explicit.
Scikit-learn documents methods that select subsets of input features for model development. Scikit-learn — feature selection.
Separate judgment and learning
Remove clearly inappropriate fields through a documented data review. If a selection method learns from data, keep it inside the appropriate training process. Otherwise, information from evaluation records can influence the chosen inputs.

Recheck practical availability
For an enquiry model, a useful field in an export may only be completed after staff have reviewed the enquiry. It cannot support an earlier automated decision without changing the workflow. Retain the input-availability explanation with the model.

Source reviewed 25 October 2026. Interpretation and original diagrams: PLUSHIP / Qunhe. Examples are illustrative.
Related reading
A Confusion Matrix Shows Which Categories a Model Mixes Up
A Pipeline Keeps Learned Preprocessing With the Model
