Lessons tagged “precision-recall”
2 published lessons with this tag.
Every filter fails in two directions
Every filter makes two kinds of mistake: it passes noise (a false positive) or it blocks signal (a false negative). Signal detection theory proves you cannot minimize both with one filter — tightening against one failure loosens the other. Filtering skill is not building a perfect filter; it is choosing, per filter, which failure is cheap and which is catastrophic, and tuning toward the cheap one.
Recall at the bottom, precision at the top
No single filter can be both safe and selective — but a cascade of filters can. The design law that makes cascades work: optimize for recall at the bottom (capture wide, miss nothing, trust nothing) and for precision at the top (only the verified reaches you). Every serious signal-processing system on earth — spam pipelines, particle detectors, immune systems — is built this way, and your information system should be too.