Advertising
Quality Score
A diagnostic rating of expected click-through rate, ad relevance and landing page experience, reported per keyword.
What makes it wrong.
The mechanism, not the warning.
Averaging Quality Score across keywords produces a number that means nothing, since it is unweighted by volume. A keyword with three impressions counts as much as one with thirty thousand.
In detail.
It is a diagnostic rather than a live input: the auction uses its own real-time signals, and the reported score is a summarised view intended to point at what to fix.
Read as three components rather than one number, it is genuinely useful, because each component has a different remedy.
Where this is measured.
Quality Score comes from Google Ads. The server page lists every tool that returns it, with its parameters.