Guidelines for reviewing Close votes
You may select filters to focus on a particular category. Selecting a set of tags you are familiar with will allow you to focus on questions within your own areas of expertise, and is highly recommended on large sites. There may still be many situations where clicking Skip is vastly preferable over hastily forming an opinion.
Each question will ask you "Should this question be closed as X?", however you may vote to close for any reason. These reasons are based on the existing close votes and recommend closure flags, and usually accurately identify the "risk" area for the post. (If the post only has recommend closure flags and no close votes, the reasons chosen by flaggers will only show in the review header, not in the close dialog itself.)
- Check to see if the question meets the criteria for any close reason, as outlined below. If you're sure that it does, click Close and choose a close reason.
- If the question does not meet the criteria for any close reason, click Leave open.
- If the question is closeable as written but can be edited to fit within the site's guidelines, click Edit. This counts the same as a Leave open review when submitted.
- If you're not sure whether a post is closeable (it isn't a clear-cut case, and you don't have enough knowledge of the subject to make a firm determination), Skip the item.
Reasons to close a post
The general explanations for close reasons are outlined below. Some sites may have more specific guidelines on when to use specific close reasons, so refer to their help centers and per-site metas for more information.
Community-specific reasons (including off-topic)
Each site has its own specific scope as to what questions are considered "good fits" for the site, and some specific types of questions may not be considered good fits even though they are related to the site's general scope. For example, on Puzzling, questions without a citation as to where the puzzle came from aren't good fits, and on Stack Overflow, questions lacking a clear example of code aren't good fits.
Note that some of the other close reasons can also apply to such questions, but you should close those with the community-specific reason that applies to them if one exists. For example, product recommendations aren't accepted on most sites as they are considered too subjective; while the "Opinion-based" close reason technically does apply to them, if a community-specific reason about recommendations exists, you should close with that. This is so that the author will be directed to more specific resources regarding their question.
You also have the option to vote to close with a custom comment reason as to why the question isn't a good fit for the site, instead of a canned reason. This is useful for questions that are blatantly off-topic (if no canned reason to that effect exists), or for questions that are just outside of a site's scope and could use clarification as to why they're not within it.
Finally, if the question isn't a good fit on that site, but would be a good fit on another site in the network, you can vote it for migration. For more information, see What is migration and how does it work?.
We regard the help center of each site as the ultimate guide to what is and isn't within the site's scope. When in doubt, consult there.
Needs details or clarity
The text in the closing dialog mostly explains the gist of this reason: This question should include more details and clarify the problem. Use this close reason if it's not clear what the author is asking or what issue they're facing, or if the question is missing significant details that would be required to come up with an answer.
Needs more focus
The text in the closing dialog is self-explanatory: This question currently includes multiple questions in one. It should focus on one problem only.
Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.
Note Gorilla v. Shark questions almost always fall under this category. However, please note there are exceptions - in Gorilla v. Shark, Jeff uses the question, "Are Google+ Circles better UX for sharing among friends than Facebook Groups?" as an imperfect but potentially salvageable question.
Remember we are asking whether an answer is found at the duplicate-linked question more so than whether the questions are identical. You should look at the question linked and verify that it has an answer to the question being proposed for closure. If it doesn't, it should not be closed as a duplicate. (You can't vote to close questions as duplicates when the proposed target has no upvoted or accepted answer(s).)
- Note that some sites may have policies that the questions should still be identical or nearly-identical to vote as a duplicate (i.e. that questions that are different but have the same answer should not be closed as duplicates). Other sites (e.g. meta sites) may allow closing questions as duplicates even if they're not asking the same question, if an answer to the proposed duplicate addresses the question.
If the proposed duplicate target is closed with another reason, then evaluate whether the question should be closed as a duplicate of that. If the question you're reviewing is of better quality than the duplicate target, leave open, and consider voting the other question as a duplicate.
If a duplicate exists for a given question, but another close reason is also applicable to that question, you should close with that other reason instead. Consider leaving a comment on the question to the duplicate. This is because some closed questions are automatically deleted by the system, and because closed questions that are migrated from other sites are marked "rejected", but questions closed as duplicates are exempt from these.
On meta sites, the above also applies on most questions; however, you do have the ability to close questions as duplicates of questions that don't have an upvoted or accepted answer. Questions that report bugs or request features that have already been reported or requested in the past, but have received no answers, should be closed as duplicates of the prior requests. See this answer for more information on meta duplicates.