Precision
Of the things the system returned, how many were right.
The fuller definition
Precision is the fraction of returned positive results that are correct under a defined matching rule: true positives divided by true positives plus false positives.
The reference set has ten relevant events. Six are found, four are missed, and two additional returned items are unsupported. This example measures extraction, not every aspect of a legal work product.
A concrete example
If an extraction returns eight events and six are valid, precision is 6/8, or 75%.
The distinction that matters
High precision can coexist with poor recall if the system returns only a few easy results.
Related terms
Where it is taught
Test an AI workflow on work you can assessSource and further reading
Anthropic · Evaluating AI agentsThe definition and example are written for this library. The link gives background, official documentation or legal authority as labelled. Legal scope depends on the jurisdiction and current text; product features depend on release and settings.