Editing Other's Answers Etiquette

Question

You see an answer which is incorrect in formatting or content, but is easily fixable. What do you do?

I see three reasonable (active) options:

1) Add a comment explaining the issue and the suggested correction.

2) Directly correct the error using the edit tool.

3) Downvote and move on (especially applicable if there are other correct answers and/or it was a content error).

Let's disregard the downvoting option for now assuming for some reason you are feeling motivated enough to make this answer right.

My tendency so far is to directly edit if the answerer is a relatively new user (especially if the error is formatting), and comment if they appear to be a more experienced user (especially if the error is content). I see the following advantages -

Commenting: Is more deferential, and allows the possibility of the suggested edit being incorrect.

Editing: Is simpler and quickly resolves the problem.

However, directly editing seems preferable for all parties in terms of efficiency, but it appears that experienced users typically find this action offensive, and even sometimes follow up with a trivial edit of their own (I presume so that the answer appears wholly theirs again).

In short: If there is definitely a mistake in an answer and you are sure you can fix it, is it preferable to leave a comment or just to fix it yourself?

A few examples of the types of errors:

a) In the context of taking a derivative: $\sin^3 x=3\sin^2 x \cos x$

b) In the context of defining a polynomial basis: $\{x^i~|~0\le 1 \le n\}$

c) Multiplying $a$ and $b$: $a.b$

Note that I am asking particularly about answers - which somehow seem more sacred to users than questions.

A related question: is there any etiquette to be observed when editing a question or an answer

Answer 1

I use edits on answers almost exclusively to fix typos - that is, to fix things which the poster probably didn't intend originally. Obviously, misspelled words and obvious grammatical errors should be fixed by edits (it'll be far harder to communicate where the error is than to just fix it anyways). This does include mathematical errors - however, one should limit the scope of this; if a single equation is in error and the error is not referenced elsewhere in the post (i.e. it is not copied into further equations, or talked about in the text), one may as well fix it with an edit.

If the error is deeper - that is, it's fairly clear that the author intended it as it was, but was wrong - then a comment is likely better. If nothing else, a comment is more likely to convince the author that they were wrong than an edit (which could be alarming), but it also offers the author the chance to determine what else in the post is wrong. I would definitely advise comments if the problem is stylistic in nature, as this requires major changes, but could go in lots of direction - so it really ought to be the author providing the creative energy for it.

Personally, I've only once undone an edit on one of my posts - and I did so because it added superfluous explanations to my answer. As a somewhat experience user, I consider it pretty surprising to receive an edit to an answer (since it's rare - not to brag, but my answers are perfect), but as long as the edit is correct, I'll appreciate it.

Answer 2

The standard that I try to adhere to is this: is it clear that they meant to write the correct thing? If a small adjustment is all it takes to make the answer correct, then editing the answer is the proper course of action. But if you'd have to rewrite the answer from scratch to make it correct, then that's what a downvote is for.

For example, an answer repeatedly refers to $\mathbb{Z}[\sqrt{-5}]$ and then at one point mentions $\mathbb{Z}[\sqrt{5}]$ but it's clear they're still talking about a domain of complex numbers. Clearly they're missing a minus sign, so editing is what should be done.

Edits should not be used for stylistic impositions, however. For example, someone writes $\textbf{Z}[\sqrt{-5}]$ I'm not going to change it to $\mathbb{Z}[\sqrt{-5}]$. But if someone writes $Z[\sqrt{-5}]$, you bet I'm changing it $\mathbb{Z}[\sqrt{-5}]$. When someone doesn't know $\rm\TeX$ but it's clear what they would have written if they did know, then that's another occasion editing the answer is appropriate.

In between the extremes of an answer incorrect because of a small oversight and of an answer incorrect because of a thorough misunderstanding of the mathematical principles at hand, we have the gray area of those answers that could become correct with several small adjustments. Maybe that's where a comment is called for, but it's going to be a judgement call.