Policy on deleting incorrect answers?

Question

At some places I've seen people advocate deleting incorrect answers. For example, in this thread: http://cstheory.stackexchange.com/questions/1555/hardness-of-node-partitioning-under-shortest-path-constraint

But sometimes incorrect answers are kept and even upvoted: http://cstheory.stackexchange.com/questions/1619/relationship-between-spacen-and-e

I just posted an incorrect answer (http://cstheory.stackexchange.com/questions/1651/hamiltonicity-of-k-regular-graphs) so I'm wondering whether to delete it or not.

What's the correct etiquette here? Is it up to the poster? Are both acceptable? Should we encourage either behaviour or just let posters decide for themselves?

Answer 1

I would like to cite a quote from Edison here. Part of it is taken from another website:

Thomas Edison tried a thousand ways to get a light bulb to work and all of them failed. Some didn't work. Some just flashed and went dead. Some only lasted a few minutes. He documented every case. Finally, he got one to work long enough that it would make sense to make it for sale to the public.

Colleagues asked him "weren't you disappointed after one thousand experiments?" He replied: "No, we now know a thousand ways not to build a light bulb."

That's exactly what I think about wrong answers. They tell other people what should be avoided, and what subtleties should be taken into account.

That said, it is the moral responsibility of the answerer to mark them as a wrong answer, and clear out what is wrong about them.

In any case, as Tsuyoshi pointed out, the answerer has also the right to delete the answer. Yet I believe that it is better to keep the answer (specially if it has not generated negative reputation), and mark it accordingly.

As a convention, I recommend the community not to down-vote marked-as-wrong answers.

Answer 2

In my personal opinion, it is up to the poster and depends on the situation.

An incorrect answer with a clear remark about its incorrectness is often informative. It often shows an incorrect approach which many people may think is correct. Also, comments to an incorrect answer sometimes contain useful information. Therefore, I do not think that an answer should be deleted just because it is incorrect.

However, a poster may delete an incorrect answer if he/she does not want to keep it (possibly because he/she does not think that it adds anything or because he/she is too embarrassed by the fact that he/she posted the incorrect answer). We should not force a poster to keep an incorrect answer just because it is instructive or its comments contain useful information.

The system encourages to delete an answer with negative score in at least two ways:

• If we delete an answer, we recover rep lost by downvotes (and lose rep gained by upvotes). Therefore, if an answer produced negative rep, we recover rep by deleting it.
• If we delete an answer with score −3 or below, we are awarded a “Peer Pressure” badge.

However, I am not sure if it is right to decide what to do according to rep or a badge.