confounding

Core statistics screening that catches people who run tests without understanding why they work. The signal is what the CLT actually licenses, and a correlation-vs-causation answer that uses Simpson's paradox to expose a confounder.

Propensity scores promise to mimic an experiment from observational data. The signal is knowing what they can and cannot fix, the overlap trap, and why IPW blows up. Here is the answer that separates careful candidates.