A field guide to the classifiers in my stack
TL;DR I count six classifiers in my daily stack. Only three of them involve a model. The other three are keyword lists and parsers, and they are the ones I trust more. The useful question for any classifier is not “how accurate is it” but “which way does it fail?” Every one of mine fails toward a human, or toward the cautious side, on purpose. Four principles I keep relearning: deterministic checks first, fail toward a human, a classifier may only tighten, and measure against a golden set instead of vibes. The most common classifier bug in my setup was classifying text instead of the thing the text describes. Measurement is uneven. I have real numbers for some of these and none for others, and I have tried to say which is which. Why a field guide I did not set out to build a classifier collection. They accumulated, one incident at a time, each time something needed to decide “is this one of those” before an action happened. Resale is the hobby that funds the hobby, and a lot of the automation around it is the same question asked in different places: should this thing be allowed to proceed? ...