How can we encourage users not to post answers to a new OP question until we get all the details?

Question

This was a question asked by a new user and there was not enough details provided by the OP in the original question. So, I asked for a clarification from the user in the comment here. I did not want to discourage the new user and wanted him to show what he had tried thus far so that he could get all the help that he needs. The OP too responded here saying he will post what he tried.

Now, in the mean time, he got an answer here. This invalidates all the comments exchanged earlier and basically the OP gets what he needs without sparing much of his effort.

I want the new users to feel at ease here but at the same time want them to show some effort on their part. From the OP's perspective, this is a completely new forum to them and we do not expect the question to be perfect.

But at least can we wait till the OP responds back showing some genuine effort before starting to answer the question?

Answer 1

There are two different issues being conflated here.

The first, as Hauke Laging notes in his answer is that, in this particular case, further clarification from the poster was not required for someone to satisfactorily answer the question. The only information still being sought was to demonstrate that the poster had made sufficient effort themselves¹.

Invalidated comments are not such a big deal, they can be deleted if they end up making no sense.

The second, more substantive issue, and one that is captured by your question title is worth some consideration. Posting an answer where the question is incomplete, ie., lacking sufficient facts or details, is essentially speculative; it is a guess as to what the correct answer might be. Filling the wiki with guesses, or hedged bets designed to garner upvotes before the complete information is available is a waste of everyone's time, and should be actively discouraged.

Of the two cases, the second is clearly pernicious; the first hardly ever so. If—as a matter of policy— we were to adopt such a punitive approach to all new questioners, demanding they show their own work prior to receiving any assistance, then the tone of the community would shift, markedly, in my opinion.

My view is that it is perfectly acceptable to ask people, particularly newcomers, politely to provide some evidence of their own effort (especially if this is a homework question), but only in cases of recidivism or blatant help vampirism should answers be withheld or questions closed.

In the case of the question that you link to, my view was that it was not homework, was a decent enough question to ask here, and the subsequent edit by the questioner suggests that it was asked in good faith. Let's encourage that behaviour.

_{1. Note: I completely support not enabling learned helplessness...}

Answer 2

The answer does obviously not "invalidate" the comments. The comments did not claim that it was not possible / difficult to give useful answers – because that was not the case (in contrast to many other questions). The request for more info was about explaining the OP's mistakes to him.

Nothing prevents the OP from showing his code. He would be stupid if he didn't care just because he has a working solution.

In any case it is ridiculous to downvote an answer to indirectly educate the OP; as it is to push someone (especially a high rep user) for something that is not even a community consensus yet (as your own wording shows).