I'm new to Stack Exchange and want to answer questions, but without 50 rep I can't post a comment asking the OP for clarification. Is there a clear guideline for what to do in this situation? (If so, can we make the guideline easy to find? Users with <50 rep are the ones least likely to know how to find that information on CV / meta.CV / meta.SE.)
As an example, I want to help Chrissy figure out How to explain when Main Effect and Interaction are not significant? but she doesn't provide details necessary to answer her question properly. Unable to request clarification in a comment, I requested clarification in an answer and did the best I could to answer the question given the sparse information provided. (As I was typing, another user requested clarification in a comment.)
What I did was explicitly against the guidelines in the window that pops up when answering a question:
Thanks for contributing an answer to Cross Validated!
Please be sure to answer the question. Provide details and share your research!
But avoid …
Asking for help, clarification, or responding to other answers.
In the SE meta I found the answer to Why do I need 50 reputation to comment? What can I do instead? which states:
But I want to contribute now. What should I do instead?
Can I put my comment in an answer?
No.
But suggests:
If you are sure you can provide a real answer, then you are of course welcome to go ahead, but make sure it's a full, valid answer to the question.
That's what I was aiming for, but given the details provided I wouldn't go so far as to say it's a full, valid answer to the question.
The question Comments incorrectly submitted as an answer instead: what should we do? addresses this topic from the point of view of a senior user cleaning up after a newbie. The 'best' answer is to let users with low rep treat the answer field like a comment field:
For people whose reputation (at the time the comment was made!) was low enough, the 'answer instead of comment' is all they can do. There is no cause to chide them.
However, other responses span the gamut from permissive to "we need to somehow reinforce that commenting is a privilege," and even "If they look like superfluous noise, then tell the author to STFU."
So is there a right answer? A best practice?