Stupid computer! Improving error messages for beginner programmers

Python is a great beginners programming language. Unfortunately, many of the exception messages coming from the standard library and parser are very unhelpful to a newbie programmer. By analysing tens of thousands of beginner programmer interactions, we identify a number of these cases. Based on our findings, we make some simple modifications to common standard library and parser error messages to provide more information about what went wrong, and to help guide the programmer to fixing the issue. We assess the effectiveness of these changes on a large set of beginner programmers, analysing whether these relatively naïve changes improve the rate of self-recovery in a teaching context, and whether these students are more likely to continue further in the course when they have to battle fewer cryptic error messages.