I have a question about my Drupal Answers post: create node--article.tpl.php to define fields
I am new to drupal and wanna know why people voted -3 for my question .
If you hover over the downvote icon you'll see this tooltip:
This question does not show any research effort; it is unclear or not useful
3 users thought that applied to your post, and downvoted it.
To avoid downvotes in the future, take some time to write a detailed question, which will be useful to future visitors searching for the same issue.
For that you'll want to include a detailed description of the problem, what steps you've take to debug/solve it yourself, if it's code then a snippet of the code that can reproduce the problem, error messages you're seeing, and so on. There's plenty of information in the help center to assist with asking good questions if you need it.
We cannot know exactly for which reason three users down-voted the question; the text you see when hovering the mouse over the down-vote arrow gives you a hint. In this case, I would bet it's because it doesn't show any research effort, or any effort to find a solution. I can imagine the users thought the question didn't show any effort in writing it, since it describe a task to achieve without any explicit question.
In short, the users are sending you a message: Don't ask this kind of questions; we don't want them in this site. Don't take it personal: The down-votes are against bad questions, not the users who ask them. You could ask a good answer, and receive more up-votes than the down-votes you received in that question.
Remember that a single up-vote for a question of yours balance two down-votes. It's pretty easy to gain reputation; just don't ask that kind of questions, with few details, and with no description of what you tried.