I'm taking the course through edX and I've just received the grade for pset1. My grade was 0.39.

Although my code has no problems, when I check it with check50, I get error messages. But not for code issues, rather, for design issues such as requesting text or displaying information. But my program outputs well according to all inputs received.

So the question is, to get a 1.0, do I just have to make it pass check50? And if it's OK should I leave it?

1 Answer 1


Your psets are graded by check50 only. So whatever check50 gives you will be what you get for your grade (smiley faces / total checks).

You say that your code is fine, but if it's not passing the check50 tests, then it is not following the specification that was given. Tweak your code to meet the tests.

  • Thanks! But in the videos David says that the psets will be corrected also according to the efficiency in the codw, so i'm guessing that just applies for real Harvard students, I'm I right? Commented Jul 22, 2014 at 1:22
  • That's right. The Harvard students are graded on multiple areas (style, efficiency, etc.) but edX is based entirely on check50.
    – curiouskiwi
    Commented Jul 22, 2014 at 1:23
  • So, even questions in the submit forms (like i.e. x.cs50.net/2014/psets/2) are not evaluated?
    – alciregi
    Commented Aug 26, 2014 at 15:50
  • 1
    The questions aren't used for grading. They are used for educational research on online learning... and to make the course better by evaluating what students are learning and what they aren't.
    – curiouskiwi
    Commented Aug 26, 2014 at 20:36
  • I don't have check50 on my system. However I know that my output is as per specifications. But the grade book seems to be deducting points for greedy.c
    – user3423
    Commented Feb 9, 2015 at 5:01

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