Each idea's year, people and institutions, and each line between ideas, carries a mark showing how it was checked.
Definitions are quoted word for word, never rewritten. For each idea the clearest accurate definition was chosen from Scholarpedia (often written by the idea's own inventors), Google's Machine Learning Glossary, Wikipedia and the founding paper, with a local model checking that each one defines that exact idea. Where none did, the idea shows a one-line editor's summary, labelled as such.
Formulas are copied exactly from the idea's Wikipedia article, together with the article's own sentence naming the symbols. A local model picked the equation each idea is known for, checked against hand-labelled examples; ideas where no equation clearly qualified show none. The interactive demos run the formula's rule on small made-up examples.
Quoted text: Scholarpedia (CC BY-NC-SA 3.0), Google Machine Learning Glossary (CC BY 4.0), Wikipedia (CC BY-SA 4.0), and paper abstracts from arXiv, © their authors. Formulas typeset with KaTeX.