Error Message Readability and Novice Debugging Performance

It is well known that programming error messages can be notoriously difficult for novices to understand, hampering progress and leading to frustration. In response, researchers have explored various approaches for enhancing such messages, yet results from this active strand of research are currently mixed. Direct comparisons of results between studies is challenging as these typically investigate different kinds of message enhancements and report results using different metrics. In addition, many prior studies have involved code writing tasks. In such cases, not all students encounter the same errors and messages, and it is difficult to isolate the time spent interpreting messages and resolving errors from the time spent writing code. In this research, we explore the effects of presenting novices with compiler error messages designed using the most recent collection of published guidelines - specifically, more easily readable, short, positive messages containing resolution hints. To accurately determine the time and effort required to read and respond to the messages, we utilise a debugging task where all students are presented the same code and therefore encounter the same errors. We present results of a randomised controlled experiment (n > 700) which shows that, compared to standard error messages, the messages we tested resulted in significantly shorter debugging times and higher self-reported scores of message usefulness for students in the very early stages of learning a new language.