The rules are clear that posters are not allowed to "debate" with reviewers. However, what kinds of discussion are allowed. Clearly it's not allowed to dispute what a reviewer says, which I fully agree with. I would guess that posting to thank people for their critiques is allowed. How about accepting and expanding on what a reviewer says? E.g. "I see what you mean about X, and I think that Y has to change as well." How about mentioning potential changes, improvements? E.g. "After thinking about your comment X I think what I need to do to improve things is Y." The rules do say not to explain what a piece is trying to convey. I can see the point of this when a story or excerpt is first published. But what about after there have been reviews. Can there be some response to critiques explaining more of the background of a story if that is a cooperative, positive, response? And under what circumstances can a reviewer respond to what an author posts in a Writing Workshop thread? Are there any such circumstances. E.g. if a reviewer posts "Yes, if you do X as you say then that would address the issues I raised?" Though in this circumstance I'm not sure that really adds much to the already posted critique.
Discussion should take place in Writing Issues, not in the Writing Workshop. The Writing Workshop must remain focused on critique. If the discussion goes beyond an assertion and one response, it no longer belongs in the critique thread. Discussion derails the work of the thread, which is the process of constructive critique. It may seem counter-intuitive, but it is NOT important that an expressed opinion be right. In many cases, there is no such absolute. What is important is to get the feedback from a reader, and to learn how to work with that feedback/ In a forum, the possibility exists for an ongoing dialogue, but that is not the case in the real world. You have to learn to work with the feedback available to you, and decide based on that alone what to act upon and what to pass up. Often, what you can take away from the feedback is that something is broken in a very different place, and that the reader therefore misunderstood your intent. In that case, the actual repair is nowhere near the point indicated by the critiquer. So back to your question, if something is raised in a critique thread that troubles you, discuss it in one of the Writing Issues forums, not in the critique thread. Part of the lesson of the Writing Workshop is maintaining your focus.
I understand that if it's something that troubles me, and I wish to discuss it in detail, that Writing Issues is the place for it. E.g. if I get a comment concerning over-use of tags in dialogue, with a recommendation to use more beats, then that's clearly a situation for Writing Issues as the conversation could get quite lengthy. From existing threads, it's clearly OK or at least common practice to thank people for their comments. It's natural for me to want to write "thanks for that, it's useful for me because . . ." where the ". . ." is something simple that does not invite further discussion. E.g. "Yes, I agree that line doesn't have the emotional depth it should do, and I'm thinking about possible solutions." It seems reasonable to me that such a statement is fine in a Workshop thread, though I'd like to hear the official view. However, I am not confident that I know where the dividing line is between a statement that clearly should stay in the Writing Workshop thread, and when it becomes necessary to discuss it in Writing Issues. It's easy to give extreme cases where it is obvious, but there are always going to be shades of grey.
I think maybe - this isn't official - but if you're having issues with a comment just ask the person who made it to elaborate on the issue. I got a comment on a particular sentence - couldn't see what was wrong with it but when another person pointed it out, I took a good look at the sentence and realized my error. I think if the discussion pertains to problems with your piece and how to fix them - than it's fine, if the topic derails into something else - i.e. writing in general, or an arguement errupts someone will step in to stop it. That's what I've noticed. I wouldn't worry too much about it.
There aren't any comments I have issues with. I've only posted two pieces so far, and the comments have been brilliant. Very helpful. I'm just trying to find out what sorts of follow-up comments are suitable for Writing Workshop, and when I need to take the discussion into Writing Issues. I only started this thread in the hope that I can avoid learning by trial and error.
Asking for a clarification is appropriate, especially when a new member makes a general comment like, "You use too many commas in some places."