Courtesy/Etiquette: Writing an Almost-Identical Answer just After the Previous.

I'm curious as to whether there is some implicit/explicit etiquette re writing an almost-identical answer just a few minutes after a previous one. I'm thinking about the issue in general, but the issue came up re this question:

Linear Dependence Of A Sum

I gave my answer just 2 minutes after Sami's answer, and no votes have been made. Is it considered etiquette to just delete my answer, since it seems to contribute little to answering the OP?

I've wondered about this too. If it is a very simple answer that didn't take me too much time, I'll just delete it. But if I've invested a lot of time in my answer, and another answer just happens to beat mine by a short period of time, I'll post mine too and let the cards fall where they may.

Incidentally, this topic is an interesting reflection of the problem of concurrent discovery in the "real world."

• Been there; done that. – dfeuer Dec 25 '13 at 18:48
• Makes sense, thanks, and will help relieve the frustration you describe. – user99680 Dec 26 '13 at 6:53

Now, if a question already has an answer and you show up 2 hours later, then I wouldn't post another answer unless you believe that you can add something. You can still provide what is essentially the same answer, but maybe you can word things a bit differently.

As a teacher, you can sometimes get surprised at how saying things only slightly different can make a big difference for the student.

So, as long as you don't purposefully copy someone's answer, then just post your answer.

As is addressed in this question/answers: Related: Letting less-reputable people answer questions I also wouldn't be discouraged by more "reputable" users posting perfect answers quickly.

• The problem with this method is that questions could end up with many duplicate answers. It could take much effort on the OPs part to deduce that they are duplicates. It is much easier for an answerer to make that deduction, since they already know their answer intimately (and usually they know the subject much better than the OP, so can reason faster, when judging duplicateness). – Bill Dubuque Dec 26 '13 at 23:56
• @BillDubuque: I guess that it in general can also be difficult for the OP to determine multiple answers as being valid. Also, if two answers are pretty much duplicates but the OP can see that, couldn't that help the OP? – Thomas Dec 27 '13 at 0:00
• @BillDubuque: Dear Bill and Thomas, One approach in this case (of posting an answer, just to discover that essentially the same answer was posted while you were writing yours) is to add a note saying that this answer is essentially the same as the other person's, which appeared while you were writing yours. This helps the OP and others be aware of the duplication (or near duplication), but avoids the other answer being "wasted" (and sometimes even very similar answers can have small differences which are interesting and potentially valuable). Regards, – Matt E Dec 28 '13 at 16:00
• It seems to me that when this happens it says something about the answer itself. – Baby Dragon Dec 29 '13 at 19:15

If you think your answer is essentially the same, both in mathematical technique and in method of explanation, then you should probably delete it. Remember, though, that you can edit your answer, even after deleting it. If you can come up with something new to add, or another way to approach it didactically, then you can edit your answer and then undelete it.

• Good idea; will try this. – user99680 Dec 26 '13 at 6:54

I don't think it is too unusual for two answers to show up very close in time and for them to be similar. Each poster is likely oblivious to what the other is doing, since they are posting at the same time.

• I find this to be the case many times. Sometimes, however, the second answer is posted over an hour or more (sometimes, days) after the first answer is posted. Obliviousness is less of an excuse then. – Ron Gordon Jan 7 '14 at 22:57
• That thar wouldn't be cricket. – ncmathsadist Jan 8 '14 at 0:45

As Matt E. suggested in the comments to Thomas's answer, if you do keep the answer, put a note at the top of your answer indicating to the OP that your answer is similar to another answer, so that they don't waste time reading both before figuring out that they are essentially the same. This saves wasted effort on the OP's part, but at the same time doesn't make the effort you put in totally useless.