Scenario You’re an R ( R Core Team, 2022) user and just fit a nice multilevel model to some grouped data and you’d like to showcase the results in a plot. In your plots, it would be ideal to express the model uncertainty with 95% interval bands. If you’re a Bayesian working with Stan-based software, such as brms ( Bürkner, 2017, 2018, 2022), this is pretty trivial. But if you’re a frequentist and like using the popular lme4 package ( Bates et al.
