Query Fan-Out

Query fan-out is what a system does when it turns a single question into several searches of its own. The person asks one thing; the assistant decides that answering it well requires four separate lookups, runs them, and composes one reply from what all four returned.

What the expansion looks like

Take a question like "is X a good option for a small team". A system answering it directly has almost nothing to work with. A system that fans it out asks several narrower things instead (what X costs, what X does, what people say about X, what the alternatives to X are) and assembles the answer from the results of those.

None of the invented queries is the question that was typed, and the person never sees them. They are the real retrieval events, though, and they are what decides which sources end up in front of the model.

Why this is the unit that matters

A page optimised for the phrase a person types is optimised for a query that may never be issued. A page that comprehensively answers the narrower things a question fans out into can be retrieved several times over for one question, once for the pricing sub-query and once for the comparison, and a source that turns up repeatedly across the set is in a strong position when the answer is composed.

This is the mechanical argument for pages that answer one thing completely rather than pages that mention many things: fan-out rewards being the best source for a specific sub-question, and a page that is nobody’s best answer to anything is retrieved for nothing.

One question people ask

Can I see the queries an assistant generated?

Sometimes, partially. Some interfaces show the searches they ran, and where they do, the list is worth reading closely: it is the clearest available picture of how a question gets decomposed in practice. But the display is a summary of the process, not a log of it, and it is not available across assistants. Treating the visible queries as indicative rather than complete is the safe reading.

Sources

This entry describes a retrieval mechanism in general terms and reports no measured figures.