<p>The <a href="https://stats.stackexchange.com/help/how-to-answer">help-page</a> mentions this (emphasis mine):</p>
<blockquote>
<p>Make sure your answer provides that – or at least a viable alternative. Your answer can say “don’t do that,” but it should also say “try this instead.” Any answer that <strong>fully addresses at least part of the question is helpful</strong> and can get the asker going in the right direction. State any limitations, assumptions or simplifications in your answer. <strong>Brevity is acceptable, but fuller explanations are better.</strong></p>
</blockquote>
<p>So, there is no doubt they are indeed <em>acceptable</em> answers. But upvoting them depends on the specific post and the overall scenario in concern.</p>
<p>Context is important and relevant here. whuber has raised a good <a href="https://stats.meta.stackexchange.com/questions/6597/how-to-vote-on-partial-answers#comment22562_6597">point</a>. The help-page again goes on in the same vein:</p>
<blockquote>
<p>Save yourself some frustration and avoid trying to answer questions which...
...are unclear or lacking specific details that can uniquely identify the problem.</p>
</blockquote>
<p>If someone has answered such ambiguous query (same in case of a broad question) and the bone of the post is seeking more information, check if it could have been possible only with leaving a comment and then may ask the answerer to do the same. However, if there is also some good advice (in the spirit of the first quoted para above) that has the potential to help OP, albeit in that ambiguous set of information, then that should be upvoted.</p>
<p>Nevertheless, answers are not monoliths - they are prone to be altered once OP has provided enough details for the responder to update their post. So, the best approach would be to wait (you can follow the post), both for OP's clarification as well as the subsequent update of the answer, if it is needed.</p>
