Estimating subgroup impacts in an RCT can be hard. An RCT by itself is usually underpowered for this task–we barely have enough data to give us an overall average, and as subgroups are smaller, they are noisier! One idea recently gaining increased traction is to augment an RCT with observational data. We might use …

Do you ever want to visualize the distribution of effects across sites in a multi-site evaluation (or meta analysis)? For example, consider a multisite trial with 30 sites, where each site is effectively a small randomized experiment. A researcher might fit a multilevel model with a random effect for the impact in each …