Build features that express the question

THE IDEA

Read the example.

Feature engineering chooses the quantities supplied to a model. Transformations, interaction terms and encodings can expose relationships that a particular model would otherwise struggle to represent. The example changes one feature’s weight in a simple score.

ŷ = w₁x₁ + w₂x₂ + …

Use it well

Define features using information available at prediction time. A feature that leaks a later outcome can make evaluation look strong while failing in actual use.