Consider the following tags:
- ordinal (678)
- ordinal-logit (3)
- ordinal-probit (1)
- ordered-logit (62)
- ordered-probit (13)
- proportional-odds (2)
The ordinal-logit, ordered-logit, and proportional-odds are 100% synonyms and refer to https://en.wikipedia.org/wiki/Ordered_logit. The ordinal-probit and ordered-probit are also synonyms and refer to the much less used https://en.wikipedia.org/wiki/Ordered_probit. Wikipedia puts these two terms together as instances of https://en.wikipedia.org/wiki/Ordinal_regression.
The biggest problem, however, is that [ordinal] contains lots of threads about this topic too, and even mentions it in the wiki excerpt ("Special kinds of analysis exist for such data, bearing adjective "ordinal", for example ordinal logistic regression"). My estimate is that there are close to 200 Qs there about ordered logit ([ordinal] [logistic]
yields 101, [ordinal] -[logistic] logistic is:question
yields another 61, [ordinal] -[logistic] is:question -logistic logit
another 37) and around 50 Qs about ordered probit.
The current situation is unacceptable. I can see three possible solutions:
Map everything to [ordinal]. Ordered logit regression should be [ordered]+[logistic], ordered probit should be [ordinal]+[probit], and no special tags.
Use [ordered-logit] and [ordered-probit] as our main tags for ordered regressions. Move relevant threads from [ordinal] in there. Rename [ordinal] into [ordinal-data] (similar to our tags [categorical-data], [binary-data], etc.). This would require a lot of retagging, but in fact we don't need to retag all ~200+50 threads, it might be enough to retag some most prominent ones (e.g. with 5+ upvotes) and leave the rest as is.
Create new tag [ordinal-regression] for both ordered logit and ordered probit, map other tags there, and proceed further as in solution #2.
I don't like #1. I don't have a strong preference between #2 and #3, perhaps a slight tendency towards #2. Note that [ordered-logit] is a relatively well-established tag, with 60+ threads.