Python Programming Errors in if-Conditionals: Novices' Reactions to Error Messages

Abstract

There is a large research body on programming errors, which, however, is mostly concerned with Java and of limited applicability to Python. In particular, Python’s syntactic structure differs significantly from Java’s, with blocks delineated by indentation as a major hallmark, say. In order to focus on issues that are structurally different from existing work in Java, our study considers if statements as they comprise some of the semantically simplest compound statements. Based on a dataset with over 700 000 error messages in Python, we sampled errors in relation to if statements and qualitatively studied their nature, structure, and what kind of issues seemed most difficult for students to resolve. The focus on a single type of program structure allows us to provide an overview that goes deeper and beyond mere frequency statistics, together with noteworthy examples of student errors that may further guide the development of automated systems.