Asked about Improving against a number
How do you know when to stop improving?
An answer that works
When several consecutive changes produce nothing, when the remaining failures are cases humans also disagree on, when further improvement costs more than it is worth, or when the test score has stopped moving while the train score keeps rising.
Reading an answer is not being able to give one. The section that teaches this is Improving against a number, 6 hours of Eval-driven development.
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