# Tag cleanup 2014 [duplicate]

Tags need a regular cleanup. There was a number of questions on particular tags recently — but (while proposals for some really major changes should, perhaps, be posted as separate questions) maybe a separate question for each case is too much.

In the past we used Tag merging and synonyms thread — but it grew too cluttered to be of much use.

Rules of the game are basically the same:

• a particularly bad tag (rule of thumb from the previous thread: «roughly speaking ... if I can't imagine a person classifying a tag as either interesting or ignored, I'm getting rid of it»),
• a tag that should be a synonym of an existing one,
• a tag that used for two or more completely unrelated things;
• upvote/downvote/comment as your agree/disagree with suggestions;
• wait a day or two before implementing suggestion;
• when retagging questions by hand please keep your rate down to a few posts a day, so not to flood the main page.
• (If you think the Tag Merging and Synonyms thread is cluttered, just wait until you get that extra 900 rep and see all the deleted answers!) – Willie Wong Jan 16 '14 at 16:31
• As you write, Tag merging and synonyms thread is quite long. That's why it is useful viewing the answers there sorted by recent activity. – Martin Sleziak Jan 16 '14 at 19:52
• @Martin I use sort by recent activity on all question (both here and on main). It doesn't solve all problems (for one thing, there comments are folded immediately — even for answers with only one comment). – Grigory M Jan 16 '14 at 20:09
• @Martin: I agree with Grigory, with almost 150 answers (included deleted), that thread is just exhausted out. Regardless to how you sort the answers. – Asaf Karagila Jan 16 '14 at 21:50
• @AsafKaragila The two most recent posts there (1 and 2) received som votes and comments and they were resolved. This at least shows that there are some people who read that thread. (Although it seems that we have digressed from the questions posted by Grigory. If needed, we can continue the discussion about the long thread in chat.) – Martin Sleziak Jan 17 '14 at 8:49
• @Martin: And I still follow that thread. But it's generally difficult to do so. – Asaf Karagila Jan 17 '14 at 8:51

Edit Renamed. Tag Wiki (Stub) will appear soon.

. What does it even mean??

If the purpose is finite elements (see Rahul's comment below) element method, then perhaps it would be a good idea rename the tag to , and if someone could add a wiki it will be great.

• There is something called the finite elements method (FEM). I know nothing of what it is, but I suspect that is what the tag may have been created for, in which case it could probably bear a rename or becoming a synonym if the other exists. – Tobias Kildetoft Jan 30 '14 at 9:01
• @Willie: Thanks! – Asaf Karagila Feb 6 '14 at 9:13
• @Willie, Asaf: Actually, the term is finite element method, no plural. Rename again? – Rahul Mar 20 '14 at 22:47
• @Rahul: Oops, fixed. – Willie Wong Mar 21 '14 at 9:30

I suggest that we remove the tag.

Most of the 13 current questions in the tag deal with properties of specific sequences listed there (and so the is perfectly suitable). Of the remaining four, three are likely off-topic on math.SE and can be deleted:

The remaining question

could/should be tagged and/or .

This tag was mentioned once in the Tagging chatroom:

tag has been created here. I am not sure whether it is needed. (Martin Sleziak)

• I am not sure whether questions about usage of OEIS and OEIS itself should be considered off-topic. According to help, questions about software that mathematicians use are on topic. We do have some questions about arxiv or wolfram-alpha, which are in similar vein as the questions you have mentioned. (On the other hand, I do not think that for the question where the tag was created it is very relevant that this sequence is listed on oeis.) – Martin Sleziak Sep 10 '14 at 7:14
• I have pinged the user who (probably) created this tag. It might be good to know also the opinion of the tag creator. – Martin Sleziak Sep 10 '14 at 7:16
• @Martin: My thoughts on the three questions I pointed as off-topic. (1) Borderline, at best. (2) Who cares? It's equivalent to "What MATLAB function has the longest name?" (3) If the OEIS has guidelines for submissions, those should be made readily available at the OEIS site. – user642796 Sep 10 '14 at 7:48
• How about we replace (oeis) with the pair (online-resources) + (sequences-and-series) for those questions listed? This tag pair correlates with OEIS pretty well. Then their topicality can be decided separately, without getting in the way of tagging decisions. – user147263 Sep 10 '14 at 11:16
• Here is a reply from the (probable) tag creator. – Martin Sleziak Dec 20 '14 at 14:48
• @MartinSleziak I don't quite understand the tag creator's argument – what material difference does it make to a question, whether or not OEIS is referenced? And "but it is not possible to unite these questions except with a tag since the A number is not known in advance (and the question doesn't always write OEIS..." is rather weak, since searching [oeis] oeis is:question returns 11 of the 13 questions currently tagged (oeis). – epimorphic Dec 21 '14 at 20:44

I propose to merge the and tags.

• Since (proof-verification) and (solution-verification) have a separate thread, it would perhaps be better to make the suggestion as an answer to that post. And I think that's it not good to ask on several things in one post, unless they are closely related. (Suppose I would like to upvote one suggestion and downvote the other one. Would should I do? Even if I want upvote one of them and I am indifferent to the other one, it seems as my vote will be misinterpreted.) – Martin Sleziak Oct 5 '14 at 8:22
• In general, I do not expect too much feedback from the community about tags - many questions about tagging don't even reach 100 views. But there are exceptions and so let's hope this is going to be one of them. I have edited your posts so that there are now links directly to the questions tagged with these tags, so that users reading your post can easily check what kind of questions are these tags used for. – Martin Sleziak Oct 5 '14 at 8:31
• I will add that if this tags are made synonyms, (morphism) should remain master tag, since it is more general. – Martin Sleziak Oct 5 '14 at 8:32

Resolved

Here are two tags I noticed:

I have no idea if either is needed, but I suspect that the second one is too specific. Probably the first one too.

If other people can weigh in, and give their opinion is great. If these tags should stay, then they really need a wiki excerpt. Especially the first one.

• Maybe classical-groups should stay. Maybe I'll try to write some tag wiki [stub] later... – Grigory M Jan 1 '15 at 19:57

I think the diamond moderators should speed up the processes on changing the singular tag names to the plural tag names, as discuss in About the plurality of tag names.

• Diamond moderators might kindly help — especially if you at least post a concrete suggestion (i.e. some list of tags needing pluralization). But really, I'm not sure this is that important... – Grigory M Jan 21 '14 at 10:55
• You may find this extremely simple data.SE query helpful in finding tags you feel should be pluralised. – user642796 Jan 21 '14 at 11:45

Also have a look at the tags at this (the meta) site, we have 6 pages of them and do we really need:

and so on?

I am not sure what to do with them, probably best to make them synonyms of other tags or merg and delete them

Also many tags don't have wiki's , that in itself is with low used tags reason for investigation

• Regarding hat, see this answer in the "Tag merging and synonyms" thread. – user642796 Jan 25 '14 at 15:44
• IMHO the device/OS/browser tags are quite useful when issues arise with using math.SE from specific platforms. These tags would help users search for information when they run into problems. – user642796 Jan 25 '14 at 15:53
• As for naming, those two questions may be of historical interest, and those issues likely won't come up again. Perhaps an early-history or similar tag should be created to encapsulate these threads. I'm mostly thinking "out loud" about this one, though. – user642796 Jan 25 '14 at 15:58

A long long time ago, in a galaxy far away this thread happened:

http://meta.math.stackexchange.com/questions/2908/should-we-have-a-lambert-w-tag/

Now I noticed that exists with roughly 40 questions. Should we let it slide, and contribute that to the immense inflation of questions and users since then, or should we hold true to that thread?

(I have no opinion on the matter, for one, and my opinion on my lack of opinion is that it's weird.)

• You're not alone in your lack of opinion, it seems. – user642796 Feb 6 '14 at 8:54
• The real question is whether I am alone on my opinion on my lack of opinion. – Asaf Karagila Feb 6 '14 at 8:55
• If the consensus in the other thread was that (lambert-w) is not needed and (special-functions) should be used instead, the easiest way to go would be to make it a synonym of (special-functions). (Of course, with (special-functions) as the master tag.) – Martin Sleziak Mar 20 '14 at 8:19
• It's up to 58 questions now. I think it deserves to live, at least because it's actually being used correctly. Users are unlikely to type "lambert" into tag without knowing what they are doing. Some tag names are lucky like that. – user147263 Sep 2 '14 at 22:22

I think should perhaps be a synonym of , to be consistent with , etc.

I just noticed that exists with 24 questions.

Do we really need it? I'm inclined to say that it can be removed. But some more input is probably a good idea.

Does anyone really care about the tag?

• I think it kind of makes sense when used in conjunction with algebra-precalculus. The latter tag is very broad, and solving a single equation vs. solving a system of equations are considered quite different topics at that level. So I don't see a particular need to remove it. There are only five questions with no other tags, two of which are closed. – user147263 Jul 29 '14 at 21:19
• (now all of those are taken care of) – user147263 Jul 29 '14 at 21:30
• This was discussed on meta in a separate thread: meta.math.stackexchange.com/questions/9989/… The consensus was to keep the tag. – Martin Sleziak Aug 4 '14 at 6:07

Can anyone guess the use of and then retag/add a tag-wiki?

Or alternatively, we may remove the tag altogether.

• Or make it a synonym of elementary-number-theory. The latter tag is among the ones most frequently missed by new users, since "number theory" is not in their vocabulary yet, and "elementary" does not help. – user147263 Aug 10 '14 at 20:09
• I support integers→elementary-number-theory — but looks like I'm the only one who have upvoted this... – Grigory M Jan 1 '15 at 18:43

Resolved: is now a synonym of

We now have tag with $59$ questions (for the most part, it was edited into old questions). It should be made a synonym of , which has $280$ questions. I see no point in having one tag for a PDE and another tag for solutions of that PDE.

Hence, I proposed making it a synonym

• done <characters> – Willie Wong Aug 29 '14 at 7:25
• @WillieWong Thanks. There are other upvoted proposals in this thread that seem to require moderator action (renaming/merging). Is there a protocol for bringing them to a mod's attention for possible action or rejection? – user147263 Aug 29 '14 at 18:48
• um... if it does require moderator action, please flag. If the situation is within the specialties of one of the mods, we can certainly expedite it. If none of the mods are familiar enough with the subject to make a comfortable decision, we may hold off and watch the comments develop a bit before we act. – Willie Wong Sep 1 '14 at 7:32

What in the world is ?

What is about? No wiki. Questions involve:

• transformations of probability distributions
• transformations of differential equations
• transformation of conic section
• transformation matrices
• Fourier transform, Abel transform, Hilbert transform, Laplace transform, Legendre transform, [any name] transform.
• any kind of linear transformation of anything
• any kind of nonlinear transformation of anything

There are 939 questions, of them about 60 have no other tag.

What Is to Be Done? Discussion here

There are three tag synonyms that were suggested but not discussed here. Since I doubt many people check regularly the "suggested" tab of the tags page, let me give them some exposure so that more people can vote on them:

The tag was suggested to become a synonym of , and was advertised here, but it still lacks enough votes in either direction. (Recall that suggested synonyms are accepted at +4 and rejected at -2; anyone with a score of 5 on the tag can vote.)

• Point set topology: chat.stackexchange.com/transcript/message/17904252#17904252 – Martin Sleziak Dec 8 '14 at 12:45
• @Martin Point taken. But I don't think people check the chat often for things like that (I know I don't). – Najib Idrissi Dec 8 '14 at 12:47
• My comment was mainly intended to give some information on when and why was this synonym suggested. (And maybe to advertise that chat room at the same time.) – Martin Sleziak Dec 8 '14 at 12:48
• I just realized the natural-numbers synonym was suggested in 2011... So there has probably been discussion about it, but I can't find it (cf. this). – Najib Idrissi Dec 8 '14 at 12:54
• Some discussion on (natural-numbers) in chat: chat.stackexchange.com/transcript/message/2575681#2575681 (From 2011, as you correctly said.) – Martin Sleziak Dec 8 '14 at 13:01
• Echoing some of the concerns raised in that chat transcript, I'm not sure that the (natural-numbers) proposal is a good idea. It looks like a majority of the questions tagged (natural-numbers) aren't about number theory. Among the related tags in the sidebar, the set theory contingent is at least as prominent. – epimorphic Dec 20 '14 at 6:41

I just saw that has been created recently, with two questions.

Being completely ignorant on the subject I have no opinion on whether or not it should be kept. But perhaps one of the other readers of this thread could weigh in.

(My default instinct is that we don't need more tags, and that tags should generally be discussed on meta before being introduced. So I'm naturally in favor of removing the tag, but I prefer if someone else judge on this.)

• I noticed it, and my first inclination was to kill it (especially after this), but then I realized that harmonic-functions would not work for these questions. Harmonic functions and Laplace's equation refer to $\Delta u=0$. Questions about operator properties of $\Delta$ usually concern its engenfunctions, $\Delta u = \lambda u$. These are not harmonic functions. Spectral theory of Laplacian is a sizable field, so I think the tag may be viable. So: I'm inclined to keep Laplacian, but merge Laplace's-equation into harmonic-functions. – user147263 Jul 17 '14 at 16:13

What is the approximate difference between and ?

(I really know nothing about the subject. I understand the difference between and , but the volume of those tags is an order of magnitude higher, which makes it really justified to have two separate tags; is it the same here?)

• Alright then. Thanks for cleaning up this issue. If someone can expand the tag excerpt a bit, it would be great. – Asaf Karagila Aug 30 '14 at 22:40
• Approximation theory is a sizable mathematical field, currently underrepresented here. But basic instances of approximation appear in calculus, e.g., "find an approximation to $\sqrt{4.01}$ using the differential". It is natural to tag this sort of question approximation, but classifying them as approximation-theory does not look natural to me. – user147263 Aug 31 '14 at 1:23
• Related discussion: meta.math.stackexchange.com/questions/4697/… – Martin Sleziak Aug 31 '14 at 4:24
• @Martin: Very related, thank you! – Asaf Karagila Aug 31 '14 at 4:33
• BTW the tag-wiki lists some topics that belong to this tag. – Martin Sleziak Aug 31 '14 at 4:44
• I believe it should read "I probably understand the difference between proba$\dots$" based on "What is the appro$\dots$" – Display Name Sep 1 '14 at 7:08

Here are a bunch of new tags which I'm not sure are needed, but I can't really say. They are off shoots from the tag, which may or may not be useful:

(Most new tags are too general, too arbitrary, or too specific; but in this case both might be worth saving.)

• My rule of thumb: if an area of math is significant enough to have its own Wikipedia article, then it can have its own tag, too. Both tags pass this test. – user147263 Sep 20 '14 at 16:31
• The one for algebraic combinatorics is not much of a Wikipedia article. – Asaf Karagila Sep 20 '14 at 17:03

The tag is meant for

Probabilites of random geometric objects having certain properties (enclosing the origin, having an acute angle, being convex, ...); expected counts, areas, ... of random geometric objects.

In reality, it's often used for problems involving geometric probability distribution $P(X=x)=p^x(1-p)$, with no geometric objects involved.

Is there a way to rename the tag so that the confusion is avoided? I could not think of one. For now, I just edited the tag excerpt to point out that geometric distribution does not belong there.

In any event, this post is meant to raise awareness than this is one of the tags with substantial percentage of posts that don't belong there.

I think we can merge the tags which are related to Maths tests like or (or whatever I am not aware of in this site) as a single tag. Another missing one is that: we can merge many tags like , and ... as Advanced Calculus. Indeed if want to do it, we will need to inform users of this new tag. Thanks

• I definitely disagree multivariable-calculus with vectors. Probably it would be better to post unrelated suggestions separately; so that users can vote on each of them. (I downvoted this post because of your suggestion on multivariable-calculus. I would not downvote the suggestion about gre.) – Martin Sleziak Sep 10 '14 at 9:16
• I have also edited your post so that there are links to tags directly. (So that users can click on them and look at the questions in those tags, tag-wiki, number of questions, etc.) – Martin Sleziak Sep 10 '14 at 9:18
• Honestly, I wonder if the (gmat-exam) and (gre-exam) tags have any value at all. They are largely used as meta-tags ("This integral question came from a practice exam!"), and IMHO the remaining handful probably don't merit a separate tag (even a (standardized-math-exams) tag). – user642796 Sep 10 '14 at 10:38
• @ArthurFischer Senior math majors studying for GRE this semester are likely to find the tag [gre-exam] useful. While the tag does not correspond to an area of mathematics, it does something to describe the content: the exam has certain scope and difficulty level, and prospective takers look for practice problems of that scope and level. I can imagine a student telling another: for GRE prep/review, look at math.stackexchange.com/questions/tagged/gre-exam ... – user147263 Sep 10 '14 at 17:12

Do we need ?

On the one hand the tag makes sense. In many occasions users ignore the tag excerpt, and just choose . In these cases I've been generally reassigning the tag to , so a new tag might make sense.

On the other hand, searching "Kalman filter" is simple enough, and it seems unlikely that a question about Kalman filters won't include the term "Kalman filter" in it. So the tag doesn't really add any advantage in this aspect.

(Edit: I have no actual issues with having this tag, but I would like more explicit support before I start retro-tagging questions; not just two downvotes and an obvious comment from Martin who started the tag.

For instance, if someone can suggest/post a tag wiki/excerpt it will be grand.)

• I created the tag. My main two reasons were: 1) Very often such questions are incorrectly tagged (filters). 2) The notion of Kalman filter seems to be rather important (as far as I can say). A little more details in chat. – Martin Sleziak Oct 2 '14 at 7:43
• I know you have, Martin, and just when I told someone that I generally remove tags which weren't discussed on meta first. And you didn't bring it up on meta, I had to do that! Shame on you! :-) – Asaf Karagila Oct 2 '14 at 7:49
• Since you are asking about more community input, should someone (for example, me or you) create a separate question for this tag? Or is it sufficient that it is mentioned here? (So, hopefully, those users who follow the posts about tagging on meta, will eventually notice this post.) – Martin Sleziak Oct 5 '14 at 7:51
• @Martin: It seems that this post goes largely unnoticed. Perhaps wait out today, and tomorrow one of us should post a separate question. – Asaf Karagila Oct 5 '14 at 8:16
• Here is separate question about this tag: meta.math.stackexchange.com/questions/16992/… – Martin Sleziak Oct 6 '14 at 15:49

Resolved: is now (without a synonym; one can be created if the singular pops up too frequently).

The tag should be pluralized, for consistency with other tags (e.g., .

• Should this even be a tag? It seems rather pointless. Sequences should cover it well enough. – Cameron Williams Nov 25 '14 at 4:06
• (sequences-and-series) grew to 13K questions, so having some more specific tags within it isn't unreasonable. They help the software pick what's more likely to be related. – user147263 Nov 25 '14 at 4:07
• Well when someone talks about sequences, they're often considering Cauchy sequences anyway. – Cameron Williams Nov 25 '14 at 4:08
• In some abstract sense, maybe. Most questions in the general sequences tag are asked by users unfamiliar with the term "Cauchy sequence". The tag is applied to problems like "prove that if $a_n$ is a Cauchy sequence, then so is $a_n^2$" and the like. Those are a distinct group of questions. – user147263 Nov 25 '14 at 4:18
• Hm. That's a fair point. – Cameron Williams Nov 25 '14 at 4:19