<p>In general specific questions are better than very broad open-ended questions (even when they're not too broad to stay open). "Add to my understanding" is not usually a good question. </p>

<p>In particular it's better to try to make a question that would be useful to the next person as well as yourself, even if a good answer ends up repeating some things you already know. </p>

<p>In addition, there's the problem that you might make your question nigh-unanswerable ("Yes, that's pretty much it" isn't really a suitable answer).</p>

<p>The main exception to this advice would be the special treatment we give to self-study questions (where describing what you already understand about the topic may be relevant).</p>
