Glossary
Extractable passage
An extractable passage is a self-contained block of text, usually opening with the answer, that a system can quote without the surrounding page.
Test it by copying only that paragraph into a blank document. If the paragraph still answers the question and names the entity, it is extractable. If it needs the previous paragraph, the headline animation, or a chart with no text, it is not.
Pages are split into chunks before a model writes. The chunk boundary will not respect a clever narrative arc. The answer has to survive being the first sentence of whatever chunk is retrieved.
Named North writes the answer in the first paragraph of each URL for this reason. The working model is how AI systems choose sources.