add 'marginaleffects'

[jpiaskowski]

marginaleffects (for prediction/estimation)

[bbolker]

There's a more general question here. Many of the "downstream" prediction/estimation/diagnostics/plotting packages can handle some subset of mixed-model packages. broom.mixed is the only one that's specific to mixed models AFAIK. This set springs to mind: performance, effects, emmeans, ggeffects, DHARMa, marginaleffects, gtsummary, stargazer, ... what should our rubric/criteria be for including these packages in this task view?

[jpiaskowski]

I'm not entirely certain, to be honest. It depends on the overall purpose of this CTV, I suppose? My view is that this should help others implement mixed models and extract needed output from them. I view emmeans, marginaleffects, etc as convenience wrappers for extracting BLUEs from mixed model objects. While it's possible to do that without those packages, they do make it easier. I don't know what those other packages do (e.g. performance), but it seems like if a package solves a needed issue and has methods specifically written for mixed model objects (e.g. merMod), then their inclusion is warranted.

[bbolker]

added.