user5771: I've seen a few questions now that have 0 answers, but have long comments that for all intents are trying to answer rather than clarify the question.
For example, this post.
When I see a comment that has an answer in it, I (and I'm sure others) feel like it would be a waste of my time to actually post an answer for the question because the information is already there. However, this could lead to some questions going without any formal answers, lowering the percentage answered and other statistics unnecessarily.
Is there a policy about this kind of comment? Should it be discouraged? How important are statistics like "percentage answered" if the questions are still getting the relevant information posted to them?
EDIT: This is a better example.

user5466: I think there should be some way to vote to convert a comment to an answer, through votes, or by a mod...As biogirl noted sometimes potential answerers are not confident and so put answers in the comments instead of an answer...at this point, other members of the community or a mod should be able to come along and confirm and convert it.

user5144: I am not sure about this sometimes as well. Depending on the length of my answer and the availibity of references for it, I rather choose to add a comment than an answer. But the idea mentioned by biogirl above to encourage people to expand comments and make them real answers is good.

user3615: I also have felt this many a times. This happens mostly because people(including me) are sometimes not sure whether their answers are "correct" and fear downvoting.
I would suggest that more experienced members and moderators view those comments and encourage the users to modify it and post it as an answer. If an answer is not provided for a long time but kinda exist in the comment , someone should sum up the discussion in the comments and post it as a community wiki. 

user948: When you click on the add comment link, the ghost text in the box says

Use comments to ask for clarification or add more information. Avoid answering questions in comments.

Additionally, the Privileges - comment everywhere page has sections entitled When should I comment? and When shouldn't I comment?:

Comments are not recommended for any of the following:
...

Answering a question or providing an alternate solution to an existing answer; instead, post an actual answer (or edit to expand an existing one);


So, what to do about it? At a minimum, @reply to the answering commenter and ask them to put their answer in an actual answer. If a situation seems to be particularly egregious, you can always flag it for moderator attention using the "other" reason.
From a broader perspective, the main reason to not put answers in comments is because comments are not indexed by the search engine, so keywords won't be found by future visitors. There may also be issues with our statistics as related to our status as a beta site, but I'm not familiar enough with that aspect of things to do much more than speculate.

5771: <p>I've seen a few questions now that have 0 answers, but have long comments that for all intents are trying to answer rather than clarify the question.</p>

<p>For example, <a href="https://biology.stackexchange.com/questions/15477/why-is-homo-sapiens-not-categorized-as-an-invasive-species">this post</a>.</p>

<p>When I see a comment that has an answer in it, I (and I'm sure others) feel like it would be a waste of my time to actually post an answer for the question because the information is already there. However, this could lead to some questions going without any formal answers, lowering the percentage answered and other statistics unnecessarily.</p>

<p>Is there a policy about this kind of comment? Should it be discouraged? How important are statistics like "percentage answered" if the questions are still getting the relevant information posted to them?</p>

<p>EDIT: <a href="https://biology.stackexchange.com/questions/14336/counterintuitive-action-of-vitamin-d">This</a> is a better example.</p>
 5466: <p>I think there should be some way to vote to convert a comment to an answer, through votes, or by a mod...As biogirl noted sometimes potential answerers are not confident and so put answers in the comments instead of an answer...at this point, other members of the community or a mod should be able to come along and confirm and convert it.</p>
 5144: <p>I am not sure about this sometimes as well. Depending on the length of my answer and the availibity of references for it, I rather choose to add a comment than an answer. But the idea mentioned by biogirl above to encourage people to expand comments and make them real answers is good.</p>
 3615: <p>I also have felt this many a times. This happens mostly because people(including me) are sometimes not sure whether their answers are "correct" and fear downvoting.</p>

<p>I would suggest that more experienced members and moderators view those comments and encourage the users to modify it and post it as an answer. If an answer is not provided for a long time but kinda exist in the comment , someone should sum up the discussion in the comments and post it as a community wiki. </p>
 948: <p>When you click on the <strong><code>add comment</code></strong> link, the ghost text in the box says</p>
<blockquote>
<p>Use comments to ask for clarification or add more information. Avoid answering questions in comments.</p>
</blockquote>
<p>Additionally, the <a href="https://biology.stackexchange.com/help/privileges/comment">Privileges - comment everywhere</a> page has sections entitled <strong><code>When should I comment?</code></strong> and <strong><code>When shouldn't I comment?</code></strong>:</p>
<blockquote>
<p>Comments are not recommended for any of the following:</p>
<p>...</p>
<ul>
<li>Answering a question or providing an alternate solution to an existing answer; instead, post an actual answer (or edit to expand an existing one);</li>
</ul>
</blockquote>
<p>So, what to do about it? At a minimum, @reply to the answering commenter and ask them to put their answer in an actual answer. If a situation seems to be particularly egregious, you can always flag it for moderator attention using the &quot;other&quot; reason.</p>
<p>From a broader perspective, the main reason to not put answers in comments is because comments are not indexed by the search engine, so keywords won't be found by future visitors. There may also be issues with our statistics as related to our status as a beta site, but I'm not familiar enough with that aspect of things to do much more than speculate.</p>
