<p>I don't think this idea has legs, mainly for the reason given by @Kelvin: there are already adequate resources in the English language to indicate just where &amp; why you have doubts about your own answer; selecting from a drop-down menu would be crude by comparison. The <a href="https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect" rel="nofollow">Dunning&ndash;Kruger effect</a> would further diminish the utility of such self-assessed confidence levels.</p>
