AI engineering glossary · Classical ML algorithms
What is ID3?
ID3: An early tree-building algorithm by Ross Quinlan that grows a tree top-down, choosing at every node the categorical feature with the highest information gain. It cannot handle numeric features or missing values directly and has no pruning step, which later methods fixed.
ID3: an example
On a weather dataset for 'play cricket?', ID3 picks 'outlook' first because it yields the largest information gain.
Related terms
More Classical ML algorithms terms
Where you learn it
ID3 is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.