Yes, it's confusing to have two modules with almost identical names. What I suggest is to rename `mixed_effects` as `bayesian_mixed_effects` but I would not merge them since they have distinct purposes IMO. `mixed_effects_stat` is about computing decision statistics for hypothesis testing, `bayesian_mixed_effects` is about computing (approximate) posteriors. So far, it implements VB only, hence the maths are very similar to `mixed_effects_stat`, but we might want to include other approximation schemes in the future, and this would make the whole thing diverge quite a lot from `mixed_effects_stat`. I think that the view points are different enough to keep things in separate modules.