I think it would be really useful to have a public decision (hopefully with input from the comm team?) on when we ought to migrate a question. There have been many, many meta posts espousing the (hopefully obvious) maxim of "Don't Migrate Crap". But it isn't always that simple, and what I am having difficulty finding is a consensus on what to do with mediocre questions that are not on topic on the original site, but are on topic on the target site.
I have my own point of view on this, which I've seen others share, and I've also seen another opinion discussed fairly often. What would be really great is to put the debate to rest and find out which is correct. If I'm wrong, I am totally okay with that. I can change, honest! I'd just like something on meta that I can point to either way, and to put the issue to bed.
As far as I can tell, there are generally four categories of questions as candidates for migration:
The question is total crap. It has no redeemable features and cannot be saved. What site it's on-topic on is irrelevant; it would be closed anywhere.
The question isn't very good, and should be closed as it stands now. But it could possibly be saved if the OP edited to add more context/details/research/clarification/answer questions left in comments.
The question is okay. It's not stellar, but if it had been posted on the target site originally, the community would probably keep it open and try to answer it.
The question is very good. It will clearly add to the quality of the target site if it is migrated. It is well developed and a quality question.
I think everyone agrees never to migrate questions of type 1, and to always migrate questions of type 4. It's #2 and #3 where views tend to differ.
Never ever migrate questions of type 2. There's very little point. Even without taking migration into account, it's a toss up whether or not the OP comes back to clarify a question. And then you have the additional hurdle of coming to a new site and possibly having to create an account... Not to get an answer to their question, but just to edit it so that maybe they'll get answers? It just doesn't happen often, in my experience. There are so many stub migrated questions from users who never came back to look at them. This doesn't add any benefit (and wastes the time of those who tried to ask for clarification, or maybe answer the question anyway). It clutters up the target site. Nothing good can come of this (okay, rarely).
Questions of type 3 should be judged on a case-by-case basis. I'm generally not in favor of migrating these either; my understanding of the purpose of migration is that if a question is super amazing and really needs to stay alive on the network, but isn't on topic on the site it was originally posted on, then you migrate. Basically the opposite of the crap maxim: Only Migrate Gold. But sometimes there's a mediocre question like this which is interesting and could do well if migrated. So I think questions like this should be migrated sparingly, and only if there's a compelling reason. But overall, I'd really prefer to just stick to questions of type 4 (migration should be the exception, not the rule).
My understanding of the opposing view:
Always migrate questions of type 3. The goal is to get as many questions as possible answered, and the question can be answered on the target site. Also this will generate more exposure to the target site because the person who asked the question has probably never heard of it (if they had, they'd likely have asked there in the first place).
Usually migrate questions of type 2. I have trouble explaining the reasons behind this one, so I'll just quote something J.R. said recently:
I would say those should be migrated. I think Wendi is referring to questions that wouldn't hold up well at either site. That said, in the case of, say, insufficient context, if it looks like ELL is the better place for the question, I think it would be better to migrate the question, and then ask for more context, and opposed to ask for more context, and then migrate the question. - J.R.
Call for consensus
So...which is it? Or is it something in between? Whatever the answer is I can accept it, I just think debating it continually isn't getting us anywhere. The whole SE network would probably be best served to pick a set of migration rules and stick with them. What does everyone think? (And if SE wants to weigh in on how they intended the system to work, that would be awesome too...)