A feature set is the selected collection of predictor variables supplied to a machine-learning model. In a classification workflow, it is separated from the target variable before training and evaluation. section 6.3.1
A practical feature-set workflow includes:
- Select relevant predictor columns and assign them to X. section 6.3.1
- Keep the target labels in y, separate from X. section 6.3.1
- Split X and y into training and test sets to measure generalization and detect overfitting. section 6.3.1
- In a random forest, evaluate a random subset of features at each tree split to increase model diversity. section 6.4.1
Football conversion model
A conversion classifier uses QUARTER, TO_GO, OFFENSIVE_TEAM_VENUE, SCORE_DIFFERENTIAL, and PLAY_TYPE as its feature set, while CONVERT supplies the labels.

