Human Intelligence Task

A Human Intelligence Task, or HIT, is one piece of work small enough that a person can finish it in seconds: label what is in this photo, transcribe this clip, decide whether these two product listings describe the same thing, answer this survey question. The name comes from Amazon Mechanical Turk, which coined it in 2005 and paid a few cents per task.

The idea behind the name is that these were jobs software could not do yet, so a human had to fill the gap. Much of the early training data for machine learning was assembled this way. As models got better at the simple tasks and worse at nothing much, the market moved towards fewer, harder, better-paid judgement calls, and Amazon closed Mechanical Turk in September 2026.