<blockquote>
  <p>there are known knowns; there are things we know we know. We also know
  there are known unknowns; that is to say we know there are some things
  we do not know. But there are also unknown unknowns -- the ones we
  don't know we don't know. -- <a href="https://en.wikipedia.org/wiki/There_are_known_knowns" rel="nofollow">D. Rumsfield</a></p>
</blockquote>

<p>The problem with using Q&amp;A sites like CrossValidated for learning new stuff is that you can only ask about <em>known unknowns</em> -- things you know that you don't know. Sites like this will never be a substitute to going through a handbook, attending lectures, or even participating in one of the multiple available online courses. Questions you ask and the answers you get cover the topics only partially. So asking multiple questions may lead to illusory and fragmentary knowledge if used instead of studying some topic by yourself. So I would say that there is also a <strong>risk for the person who asks</strong> the multiple questions of gaining false sense of knowledge.</p>
