<skill_content>
<overview> Randomized Controlled Trials (RCTs) are the gold standard for causal inference when randomization is feasible. Random assignment eliminates selection bias and balances observed and unobserved confounders in expectation, enabling clean identification of treatment effects. Strong RCT design requires careful attention to power, ethics, implementation fidelity, and threats to validity.
RCTs answer "does X cause Y?" with minimal assumptions. </overview>
<mandatory_requir
[Description truncada. Veja o README completo no GitHub.]