The Effect of Richer Visualizations on Code Comprehension

Researchers often introduce visual tools to programming environments in order to facilitate program comprehension, reduce navigation times, and help developers answer difficult questions. Syntax highlighting is the main visual lens through which developers perceive their code, and yet its effects and the effects of richer code presentations on code comprehension have not been evaluated systematically. We present a rigorous user study comparing mainstream syntax highlighting to two visually-enhanced presentations of code. Our results show that: (1) richer code visualizations reduce the time necessary to answer questions about code features, and (2) contrary to the subjective perception of developers, richer code visualizations do not lead to visual overload. Based on our results we outline practical recommendations for tool designers.