What to do about long discussions in comments? And how to avoid?

Question

For the question Example of non-locally integrable $f$ that $\int_\Omega f\varphi=0$. I had quite a long, but also quite a useful and insightful, conversation with someone in the comments of the OP about the question. After a few comments the message "Please avoid extended discussions in comments. Would you like to automatically move this discussion to chat?" appeared. Both probably thinking it wasn't going to be a much longer conversation, we kept on going. But by now it has definitely become an "extended discussion".

I understand in an ideal case, we would have moved the discussion to chat at a much earlier stage. However, I don't know if there's something we can do about it now. Since we came to a conclusion, I made an answer out of it, also summarizing the important points of the conversation. I then suggested to the other person to delete the conversation. He (in my opinion rightfully so) questioned my suggestion, stating conversations and thought processes can be helpful for others as well. I do not know what to do now.

I have one more question on this topic. How do you notice when a conversation becomes an "extended discussion"? When should you "move the discussion to chat"? I noticed the message only appears after a few comments have already been written. Is it always a good idea to "move the discussion to chat" when the message appears?

Answer 1

Most of us have experienced a time when someone asked a question during class or a talk, then followed up with a further question, then another, until the speaker has to ask them to discuss the issue personally after the talk or during office hours, for the sake of moving on.

This is a very similar situation to what is envisioned by extended discussion. Rather than a simple follow up, the comments become a dialog that looks more like a conversation than a Q&A. It's not so much that the comments have gotten too long, but too chatty.

Most commonly this happens when a user is tutoring someone, or addressing multiple follow ups from the user that significantly diverge from the scope of the original question. It's best to tidy these up by moving them to chat, where observers can view them as a standalone conversation. It's also useful to keep in mind that comments are not guaranteed to be permanent on SE, and so should be synthesized into an answer if they come to a conclusion that is important and relevant.