7.2 Types of Machine Learning

Machine learning is usually grouped into three main types. Supervised learning uses labelled data (each example has a known answer). Unsupervised learning finds hidden structure in data that has no labels. Reinforcement learning trains an agent to act by rewarding good decisions and penalising bad ones.

Example: predicting a house price from its size and location is supervised. Grouping market customers into segments by buying habits (without pre-set labels) is unsupervised. A delivery robot learning the fastest route through Addis Ababa traffic by trial and reward is reinforcement learning.