I've recently seen several posts with close votes without any comment indicating the author what the problem is. If the author doesn't have enough reputation to view close votes, he gets no feedback that he should improve his question (otherwise, he might have done so between the 1st and the 3rd close votes).
Even worse, regularly the reasons to close seem (to me) to be wrong.
Wouldn't it be better to ask (or even impose?) that each close vote is accompanied by a comment stating that there was a close vote, and WHY (I find it sometimes unclear why the voter thinks the topic is off/topic or opinion based for example)?
Are old AC transformers dangerous: it got one close vote for "Needs details or clarity", but no comment indicating so. The author (with 153 rep) has no way to know it, and no indication what additional information he should add. Even for me, it isn't clear which information is missing (even if I agree that it isn't a great question): the only useful information I see that might have been added would be the datasheet of the transformer, but I doubt it is possible to find it.
Electrical gloves: same size for the leather gloves? A question I asked some time back about electrical safety gloves (more precisely, if the leather gloves need to be the same size than the latex gloves). I considered it to be on topic (even if I admit it's not the most interesting question I asked). I would have understood if someone had voted to close it as off-topic (electrical safety equipment is not directly engineering, even if it is required when working as an electrical engineer). I might even have been misinterpreted as asking for shopping advice or been considered to broad (if someone wanted to get a link to the specific gloves, even if it would then be dangerously close to shopping advice). However, the reason given was "opinion based", I have no idea why: either latex and leather layers are usually (or always) bought in the same size, or usually/always with the leather ones one size bigger, or it depends (on either brand or exact size of hands). Either of the 3 answers would have been fine, and I expect anyone having used tens of different pairs of isolating gloves to know which one is correct.
Component that can display state without power: The author asks what devices can display a binary state without being powered on, in addition of "flip-dots and e-ink" they already know. It was voted to close as "opinion based". How can it be: an answer will contain one/several devices that match the constraints, and it is easy to verify they do. Asking for a list is maybe not very elegant, but it's very factual. Author (with rep 12) can't know the close vote.
How can I specify transformer part number in BOM for manufacturing? 2 up votes, and 2 close votes for "Needs details or clarity" (it already got 2 answers, but I agree that more details might be helpful), but nobody asked for more details in the comments. How can the user (63 rep) guess that more detail is needed if nobody asks and the question is even upvoted?
So what do you think about encouraging (or even imposing) to add a comment explaining a close vote when casting one?
So far the pros I see are:
Authors know about the close vote, and get time before the question gets closed.
Authors understand what EXACTLY is the problem (often it it not very clear why someone thinks a topic is off-topic/opinion based/... or what details/clarification is needed). And sometimes it is evident for someone experienced, but can't be guessed by the author due to his lack of knowledge about the topic (for example, for the question about the transformer: someone used to work with transformers realizes easily that specifications are missing, but someone new to transformers will think they provided all that is needed).
It is possible to answer/discuss the reason of the close vote (for example, some questions are closed as asking for shopping advice when OP is just interested in some general aspects and don't want specific shopping advice).
Other members learn about what is or not accepted on the site (I have never found a page with a clear guide on what is or is not on topic, except this and that, which still leaves a huge gray area in between what is allowed and what's not.
It prevents the anonymity of vote to close: this might help reduce the risk of abuse of vote to close, vote to close because someone doesn't like the question, or the risk of someone voting to close without being sure/mastering the subject/carefully reading the question.
- It takes a bit of extra time, so people might be less willing to vote to close (so we might have a few more bad questions not closed).