A Tool to Teach Expressions with Feedback About Broken Laws

Abstract

We developed a web-based tool for learning the order of evaluating expressions in C++ and Python languages. The variety of operator precedence and associativity among programming languages and the lack of direct visualization make understanding expression evaluation difficult for some students. The key feature of the new system is a detailed explanation of errors, containing fault reasons---the subject domain laws that the student violated. We evaluated the tool with 14 first-year Computer Science students and received positive feedback. This tool can be used for learning new concepts during homework without requiring more class time because it provides enough feedback for students to learn on their own.