If there is no sign of research effort and the question is not useful to the community because of the lack of research effort, thanthen feel free to downvote.
There are useful questions to the community that nevertheless do not show research effort. You can downvote those if you like, but never close them. Remember, there's no lower threshold for research needed for questions. We want to keep questions that are useful to the community open to the community. Here are some examples:
- How do I install Steam on Ubuntu?
- How can I change the clock in GNOME from 24 hour format to 12 hour format, or vice-versa?
- How do I empty the trash folder?
If you feel that the questioner is being lazy, and you don't want to do the work of researching the answer for them, that's OK! Don't. Just leave the question open for members of the community who do want to contribute answers in this way.
We want answers to these questions on AskUbuntu, even if the answer is already elsewhere on the web, for many reasons.