&gt; If 90% of your students fail your exam what have you learned?<p>It depends if I have corroborating information.<p>Normally, it means that they are lacking some very fundamental piece to their learning.  The last class I taught that this happened in had a particularly poor Data Structures teacher and so didn&#x27;t understand Hashes&#x2F;Dicts&#x2F;Associative Lists and how to use them.<p>Yeah, that assignment didn&#x27;t go well for about 30% of the class.  I had to back up and teach that piece.<p>However, my first assignment <i>ALWAYS</i> has 40+% failure rate.  And my assignment is: &quot;Here are the directions to: set up Eclipse, set up Mercurial, type in this program, compile it, run it, and check it in so I can run the automated tester on it.&quot;<p>I literally give people a document with <i>every single step</i> documented.  I&#x27;m not joking.  We&#x27;re talking a single print statement that prints &quot;Hello, World!&quot;.<p>40%+ always fail.  It&#x27;s almost invariant.  Nothing I do can budge that number.  I want to bang my head off the desk at the office hours just before and after that assignment.