Definition
Plain language
Of the things a system flagged, how many it got right.
As stated in the literature
The fraction of positive predictions that are true positives; paired with recall and summarized by F1.
Why it matters: It tells you how trustworthy a system's alerts are, since low precision means many of its flags are false alarms.
For example, if a detector flags 100 emails as spam and 90 truly are spam, its precision is 90%.
Heard on the show
“Think of symbolic execution as a precision instrument.”Episode 014 — Why a Constrained Pipeline Beat a Full Coding Agent at Finding Bugs 30-to-1