The heuristic I use for distinguishing between statistical modelling, machine learning and AI is is through feature engineering and model specification:

- Statistical modelling: Manual feature engineering, manual model specification (y = ax + b)

- Machine learning: Manual feature engineering, automated model specification (y = ax + b or y = ax^2 + b, I don't care, the algorithm should figure it out).

- AI: Automated feature engineering (e.g. CNN), automated model specification