How do we handle duplicate answers?

Question

Preface: I have read the original question, and the followup. However, there doesn't seem to be any consensus on what should be done with them.

Introduction
As Arqade grows, we are attracting lots of new users. Many of these users will attempt to contribute to the site by providing an answer to an old question that has already been answered. The vast majority of these new answers will provide no additional information.

This especially happens during game promotion events, as participants try to meet the promotion goals.

Generally, we have three actions we can take on these answers:

1. Upvote
2. Downvote
3. Delete

Quoting @bwarner's answer on the original question:

I've had the same thoughts. Part of me thought that we should purge them with fire. But then I started thinking about what things must look like from the perspective of these new users.

They find a new gaming site. It looks like it might be kind of cool. So they start searching for their favorite games. Finally they find a question that they know the answer to. Mustering their courage, they decide to de-lurk, create a login, and actually participate in the site. They answer the question (which happens to have a duplicate, already accepted answer). What happens next?

A) The user gets an upvote. They think "Cool, now I'm earning rep. I want to find more questions that I can answer. This site is great!"

B) The user gets a downvote and a polite comment. They think "Oh, I guess I don't know what I'm doing". They go back into lurker mode, eventually finding the courage to try again, or moving on to some other site.

C) The user's answer gets deleted. Maybe the same result as B. Or maybe they get confused, wondering what they did wrong. Or maybe they get defensive and say "Who needs this site anyway? It's just a bunch of elitist jerks."

Clearly B and C are not the end result we want. So we need to decide whether the duplicate answers really cause problems, or whether it might be an acceptable price to give people a "safe entry" into participating in the community.

He missed the current scenario: We do nothing. The user sees no response to his attempt at contribution, and decides the site has nothing to offer him.

Three of the four scenarios result in the user leaving or otherwise not contributing to the site.

We have an option available that indirectly deal with this issue: protect the question, preventing new users from contributing. Perhaps we want to auto-protect questions after a certain time period, to prevent resurrection of questions that have served their purpose. This is already being done by @agent86 on dragonvale questions to prevent poor and low quality answers, so we do have a precedent.

Options
We have a few actions we can do:

1. Edit the answer to be better quality - We would have one or more answers that provide the same information.
2. Delete the duplicate answer - The answer provides no additional value, so the deletion of it will not devalue the existing answers. We would most likely lose new users, however.
3. Protect the question pre-emptively - Essentially doing #2 before we can garner poor or duplicate answers.
4. Continue to do nothing - We can continue to accumulate duplicate answers and not encourage or discourage them.

Closing

I foresee that this problem will continue to grow. A clear consensus on actions to take would benefit the site and provide a policy that we can use to continue improving the site.

Answer 1

My vote is to delete the answer.

We are not in the business of coddling new users. If a new user posts an answer that provides no additional value, there are a few likely reasons:

• The user has either not read the current answers in their haste to provide their own answer.
• The user is trying to gain rep by paraphrasing an existing answer.
• The user has read the existing answers, and added their answer anyways.

In any of these scenarios, the user is not providing a contribution to the site. The purpose of Arqade is to provide expert answers. The StackExchange network's goal is to improve the Internet. The user's answer does not contribute to either of these goals.

Downvoting or deleting their answer will probably cause the user to stop contributing to the site. The critical difference, however, is that downvoting leaves their answer visible to all. This answer provides no additional value, and by leaving duplicate answers, we are retaining broken windows. Users may not see these due to good answers rising to the top, but the fact is, they're still there.

Editing their answer to make it better will turn it into a duplicate of an existing answer, which still provides no additional value.

In addition, the FAQ reads:

Answers that do not fundamentally answer the question may be removed. This includes answers that are …

• commentary on the question or other answers
• asking another, different question
• “thanks!” or “me too!” responses
• exact duplicates of other answers
• barely more than a link to an external site
• not even a partial answer to the actual question

If you wish to improve an existing answer, click edit.

I have bolded the relevant item. Our FAQ says we can delete answers that are duplicates. They might not be exact duplicates due to being poorly worded or paraphrased, but they are duplicates to my definition.

Do we really want to retain users that can't or won't even read the FAQ? I say no.

Answer 2

The way I see it, there are three main actions we should take for duplicate answers, depending on the kind of duplicate they are.

1. Exact Duplicate - For answers that appear to contain no new information at all, I think it is appropriate and necessary to delete them. It will certainly lead to some new user confusion and possibly hard feelings as bwarner points out, but I believe the site-wide cleanliness benefit outweighs that.
2. Partial Duplicate - Any answer which has a salvagable portion of new information, should be edited and retained. The community can decide if that information is value able with downvotes, and the asker with the check. When editing such an answer for new users, an explanatory comment should be left. In contrast to fbueckert's opinion, I believe we are all in the business of training new users to be part of our community at all times (whether we like it or not). Editing to salvage good content will teach new users that is a behavior they should emulate.
3. Magnet Questions - Certain questions attract new users (and that is a good thing). When such a question or class of questions is identified, flagging the question for protection is appropriate and I believe it rarely causes harm to the site. In fact I think the new users that will flood into that question will see the protection warning, and it will begin to provide them education on the site policy of unique answers.

tl;dr : Deleting Exact duplicates is a no-brainer, but we should use the tools we have to salvage new information and to train good new users (which is our job).