This workshop provides practical training in conducting difference-in-differences (DiD) analyses using R for policy evaluation. Participants will learn to implement both classical two-period DiD models and modern event study designs to assess policy effects over time. Using example datasets and step-by-step R code, the session will cover basic DiD estimation, visualization of event study dynamics, and key diagnostic checks, including assessment of parallel trends. The workshop is designed for students and researchers interested in causal inference and policy evaluation. Basic familiarity with R and regression analysis is recommended.