Q:

Conventions on downvoting

I have recently been reflecting on my voting patterns. The discussion on this answer suggests that different people have different views on downvoting. I thought it would be good to figure out what the community thinks should be rule-of-thumb guidelines on downvoting.
I usually downvoted questions if they are poorly written and show little effort on the part of the asker (and if there was edits made to improve the question, I would cancel my downvote) or if I think they are out-of-scope for cstheory.
For answers I usually downvote if they don't answer the question or if they are incorrect. However, I sometimes downvote answers to a homework question, especially if its a homework-level answers.
For answers on community-wiki questions I vote much more aggressively, sometimes downvoting something if I don't agree with or the answer is not insightful (especially for big list questions).
I thought this voting strategy is reasonable, but looking at the stats suggests that I downvoted a lot more than everybody else. In particular I think I have the highest total downvotes (~99) and one of the highest downvote percentages (~10%). How should I adjust my downvoting?
Also, there is some general downvoting differences between our top 20 rep users, and the MO top 20 rep users. In particular, it seems MO is more willing to downvote:

% down | MO | TCS
0.x% | 4  | 7
1.x% | 1 | 2
2.x% | 2 | 3
3.x% | 2 | 2
4.x% | 4 | 2
> 5% | 7 | 4

That might mean a difference in convention or cstheory just has higher quality questions and answers.
What are the conventions and norms for down-voting on cstheory?

A:

Here is my two cents:

Down voting a post (answer/question) without commenting is NOT OK, it is against the norm, this is discussed in the last town hall meeting and there seemed to be a consensus among the people attending the meeting. Without a comment the purpose of the down-vote is not clear, it is not a constructive down-vote, and a user answering the question can get confused because he or she might not understand what is wrong with the answer or what behavior is being criticized.
I don't find down-voting answers just because of answering a question reasonable. If the user answering the question has not done anything unreasonable and the answer is OK it does not deserve a down-vote IMO. 
On the other hand, it might be reasonable to down vote an answer when its poster has done something unreasonable or against the norms, e.g. answering a question which is clearly homework (not just off-topic), it can be reasonable in such situation because the user is violating an agreed norm about not answering homework questions (and note that even in these cases the down-vote should be explained in a comment).
If an answer is not: a. correct, b. well-written, c. an answer to the question; i.e. it is not a good answer to the question then it is reasonable (and even sometimes encouraged) to down-vote it, (but again, even in these cases the down-vote should be explained in a comment).

A:

I think your policy is quite reasonable. I don't downvote a lot because I've been in the habit of trying to encourage people (especially new ones) to continue contributing, so I merely comment if I think something's off. But I don't think everyone needs to do that (I mainly did it when trying to grow the site originally)

