[1] CAUSATION: Causal inference, quasi-experimental designs (matching designs, propensity score designs, regression discontinuity designs, interrupted time series designs), causal diagrams, structural causal models, causal mediation analysis, time-varying treatment regimes.
[2] REPLICATION: Replication designs & reproducibility, design replication studies (within-study comparisons) for evaluating quasi-experimental designs.
[3] SURVEY DESIGN: Factorial survey, experimental vignette designs.