Introduces causal inference approaches, including causal diagrams and counterfactual theory. Draws upon personal research experiences and/or prior training. Covers insights on how to apply the fundamental concepts of counterfactuals and causal diagrams; assess threats to validity in study designs and analysis including confounding, selection bias, and measurement error/misclassification; evaluate the validity of a research study’s design and analysis with respect to addressing causal questions; and critically analyze scientific literature and apply findings to decisions. Offers students an opportunity to think critically and rigorously about the implications of study design and analysis toward addressing questions.