Recently I have been reading quite a lot on CV about fixed / random / mixed effects models and related terminological controversies. Unfortunately, the CV tags for the mixed models are a mess, which does not help navigating the questions (which is a pity, given that the topic is confusing enough).
Namely, there is mixed-model tag (689 1214 questions, nice wiki), mixed-effect tag (95 305 questions, worse wiki), and also mixed tag (28 61 questions, no wiki). I do know that terms fixed and random are used differently by different people, but as far as I understand, mixed is mixed. So I think these three tags should be merged.
I think the master tag should be mixed-model, and the other two can be merged into it.
The two related tags are called random-effects-model and fixed-effects-model, so originally I wrote here that the best name for the merged tag would be [mixed-effects-model]
(which currently does not exist at all); however, on reflection, "mixed model" seems to be a more standard terminology.
This issue was brought up multiple times on Meta, but stays unresolved.
Here I suggested the same thing yesterday and @gung commented that it seems reasonable.
In 2012 a bunch of related tags was discussed with the same suggestion about "mixed" tags, and I can see no counter-arguments in the discussion (even in the careful reply of @StasK).
In 2011 a related question was asked, and @chl reported in the comments that he merged [mixed-model] and [mixed-effects-model] (the latter tag does not exist anymore).
In 2013 @Randel left a comment in the above thread suggesting the same thing as I do here, and @AndyW and @chl agreed.
multilevel
(evenhierarchical
) should be lumped in themixed effects
tag. For a beginner I think the former terms make things easier to understand, whereas thefixed/random
terminology can be a bit off-putting at first. $\endgroup$