The discussion of the division of dimension-theory seems no longer to appear on the community bulletin (14 days have passed).

Now, what's the next action?

@YuiToCheng Well, one possibility would be to post a separate question about vector-space-dimension (or whatever the name for a tag for dimension in this sense would be). Certainly, the recent discussion about dimension-theory would be linked there - perhaps there is some chance that this would attract a few more views to that question.

I think that discussion whether or not there should be a tag for dimension of vector spaces deserves a separate question. (Although in my opinion the most likely outcome is going to be that it's not really needed.)

And probably at some point we'll have to discuss that - either now or at some point in the future.

I have already linked to it - but here's a short discussion with Daniel Fischer about such tags from 2016: chat.stackexchange.com/rooms/2165/conversation/…

BTW if somebody wants to help with cleaning up (dimension-theory) from the questions that are about dimension of vector spaces, here are a few questions that might need attention: chat.stackexchange.com/transcript/3740/2019/4/26

If the division is going to take place, how are we going to do it? Create a new tag and retag everything manually?

At least for one of those tags this is the only way I see.

Let me explain in more detail.

Let's assume that the tags are going to be called dimension-theory-analysis and dimension-theory-algebra.

Then the process might work like this.

We go through the questions and retag all questions which should be under dimension-theory-algebra.

After this is done, the moderators can rename dimension-theory to dimension-theory-analysis. (If we have retagged the posts correctly, all the remaining ones should belong to that tag.)

Moderators can change name of the tag to a different name without bumping any questions - details can be found here; How to rename a tag? and Can you change the name of a tag?

So if we are able to achieve the state where all posts in (dimension-theory) are such posts which should be tagged (dimension-theory-analysis), then the rest can be done quickly and without any bumping - but some help from moderators is needed for that.

Do moderators have the power to separate all questions under dimension-theory with either of the following tags, say, commutative-algebra, krull-dimension, algebraic-geometry, and retag them dimension-theory-algebra?

You mean automatically retagging posts tagged dimension-theory+commutative-algebra with (dimension-theory-algebra) and some other similar ways to find posts by some criteria and add a specific tag?

Yeah

I don't think moderators have any possibility to something like that.

Probably people with access to the database (i.e., Stack Exchange employees) could be able to do stuff like that. (After all there were various edits done without bumping, for example, http -> https. So I assume doing something similar for tags would be possible.)

However, I am not aware of past instance where something like this was done for tags. (And I suppose that if there was something like that on Mathematics Stack Exchange I would remember.)

And the instances of such edits without bumping that I have seen were for things which were on much larger scale than this.

OK. Btw, I don't think to have another discussion of vector-space-dimension will draw much attention to the original matter.

Maybe we should act now.

Well, there's certainly no need to hurry.

But at the very least, before creation of the new tag and starting the retagging, I think it would be reasonable to consult quid. (From the moderators, quid seems to be most often involved in tag related issues.)

Today I have some teaching duties, I would probably be able to make a post about (vector-space-dimension) tomorrow.

But if you think it's about time to start, we can try to ping quid now to find out what they think about this.

I'm not in a hurry too. But if no actions are taken after having multiple threads, the discussion is superficial at best.

And of course, we might try to ask also other who were involved in the discussion about the tag whether they consider the results of the discussion (and voting) sufficient to start with the retagging. (I think Andrews, Arctic Char and Xander Henderson were involved in this discussion. Maybe I have forgotten somebody.)

@YuiToCheng Well, actually there was only one thread about the split. (The older one was about clarifying the usage of (dimension-theory).)

I certainly agree that we should not leave the things unresolved after the discussion was finished. (This seems more typical for MathOverflow.)

But I would not like starting a large ratagging effort prematurely either. (And I estimate that we'll need to retag about 100 questions, perhaps even more.)

I guess that questions about dimension in the sense of linear algebra/vector spaces has been mostly cleaned from the (dimension-theory) tag, so some work has already been done.

Thanks to all users who helped with the retagging: data.stackexchange.com/math/revision/1038474/1282557/… data.stackexchange.com/math/revision/1038477/1282560/…

Yeah, that's an achievement. I think it's an almost universal agreement that they don't belong to dimension-theory.

(0 downvotes on your answer)

I'll just ask some users who were involved in this discussion whether they think that this was discussed enough and the voting so far shows at least some consensus - and whether we should start with retagging.

If we decide to go, I'd suggest to: 1. Created the dimension-theory-algebra tag. 2. Retag those questions which should have this tag. 3. Retag other questions which do not belong under the analytic/topological meaning of dimension theory. 4. Ask the moderators to rename dimension-theory to dimension-theory-analysis.

@Andrews and @XanderHenderson What do you think about this?

@ArcticChar You have been involved in this discussion too - so probably it's reasonable to ask also for your opinion.

@quid Since you seem to be the moderator who discusses the tag-related stuff most often, input from you would be certainly valuable, too.

Basically I am asking whether we should start the process of dividing the tag.

I'll follow the majority.

@MartinSleziak Yes. Do this.

Though perhaps we should agree on a tag description for dimension-theory-algebra before the tag is created?

Meaning that we really need an algebraist to weigh in... :\

Well, if we don't find somebody knowledgeable we could simply enumerate there various type of dimension - as the ones mentioned in the Wikipedia article, Krull dimension and some others which I mentioned here: chat.stackexchange.com/transcript/3740?m=49972529#49972529

@XanderHenderson I have pinged rschwieb and asked whether they would have time to look at this.

It's a user who is active in some chatrooms - so at least it was possible to reach them. And they are also knowledgeable in ring theory: math.stackexchange.com/tags/ring-theory/topusers math.stackexchange.com/help/badges/425/ring-theory

BTW there is also a question who should create the new tag - probably someone who does not have the taxonomist badge yet.

@MartinSleziak This seems sensible... I don't think any of the disciplines that use a notion of dimension (all disciplines?) have any special conventions that wouldn't work with this.

"dimension theory algebra" seems OK to cover any sort of ring or module theoretic dimension I can think of.

Hmm, so a tag description is in the offing too, eh

I'd be happy to take a whack at it

@XanderHenderson Do I need to wait for consensus on a description or am I free to go ahead and base it on the suggestions you and Martin talked about at the meta topic?

@MartinSleziak @XanderHenderson One thing that nobody seemed to touch on yet is that many things that could be considered dimensions are also called "ranks." It seems good to me to put those under the umbrella too, but I'm open to objections.

For questions about notions of dimension, rank, or length used in abstract algebra (e.g. Krull dimension, homological dimensions, composition length, Goldie dimension). Questions about dimension of vector spaces, and rank of linear transformations are better placed under the [linear-algebra] tag.

Thanks for looking at this!

@rschwieb This looks good to me. Thanks!

Perhaps you should just create the tag---I'll work on retagging a little when I get some time.

ok

i already have a candidate

@rschwieb I apologize if I missed somebody - but it seems to me that most people that discussed the split of the tag know only very basic stuff about dimension in ring theory/commutative algebra. (Personally, I do not know anything beyond having read the Wikipedia article.) So it's best if we rely on an expert on this.

Speaking of the tag-info, would the current version of tag-info for dimension theory - math.stackexchange.com/posts/246559/revisions math.stackexchange.com/posts/246558/revisions - be suitable for the new dimension-theory-analysis tag.

BTW it's good that you included the part about linear algebra, the tag with such name (or basically any name containing "dimension") is very likely to be used for such questions by less experienced users.

@MartinSleziak I'm not sure I know anything particularly more than you or Xander does about the subject. But I do think that the subject cuts a sizable swath through the whole subject, so it seems to be a reasonable tag.

I can probably name a dozen different algebraic notions of dimension or rank... does that qualify me? :P

I had the same feeling you had about keeping the linear algebra piece out of it.

@MartinSleziak I recall a nice expository survey in BAMS by Yuri Manin: The notion of dimension in geometry and algebra which might prove helpful.

@MartinSleziak That tag needs some work, and has needed work for quite a while now. I have plans for it, but have had little time to actually deal with it. For the time being, the tag information for dimension-theory is fine for dimension-theory-analysis.

Also, isn't it possible to put warnings on tags? I.e. when a user tries to use particular tags, a warning pops up to say "Hey, maybe don't do that?"

@XanderHenderson There is such possibility, see: Do we want tag warnings, and for which tags? However, as far as I can say, SE staff is not too keen on creating such warning - so far none of the suggestions from that thread has been implemented. See also the response from quid here: chat.stackexchange.com/transcript/83225/2019/4/21

@MartinSleziak Well, darn.

Well, maybe if more people try to put some pressure on this, there's at least some chance. I do not know much other than what I heard from quid. (I should thank him for at least trying to get this implemented.)

I just suggested some edits for dimension-theory

math.stackexchange.com/review/suggested-edits/1194912

math.stackexchange.com/review/suggested-edits/1194911