Assess ability to identify and analyze internal and external validity threats in quasi-experimental educational intervention studies and to evaluate and justify statistical remediation strategies (e.g., matching/propensity scores, regression adjustment, difference‑in‑differences, synthetic control, instrumental variables, multilevel modeling, robust SEs, and sensitivity analyses). Tasks will include diagnosing threats (selection, attrition, maturation, history, instrumentation, testing, diffusion), selecting appropriate analytic fixes, specifying model adjustments, and interpreting implications for causal inference and generalizability.