The consistent bump in the 0% bucket suggests that there is a significant measurement error going on here. The author acknowledges this: > So if any of these

The consistent bump in the 0% bucket suggests that there is a significant measurement error going on here. The author acknowledges this: > So if any of these codebases are using a different framework, they’ll be counted as non-test codebases (which I recognize as a threat to validity). I'm inclined to say the 0% bucket should be thrown out, since it's impossible to disambiguate between "no tests" and "tests I can't detect". All of the other buckets are quite likely to be correctly classified.