Understanding Program Visualizations in the Wild

Visualizations play a significant role in writing, debugging, profiling, and generally understanding programs. However, little work has been done to understand the structure of program visualizations at a fundamental level— namely, why and how they scale. Previous work on visualization comprehension focuses narrowly on a few domains or on surface-level details. While this work makes it possible to point out how different features of two vastly different visualizations may be independently effective, it does not provide an underlying theory that explains both. We develop a theory of the interpretability of program visualizations focused on their abstraction and composition properties. We summarize the preliminary results from our grounded theory study of open-source software visualizations, comprising more than 150 examples. Finally, we hint at work-in-progress to experimentally confirm our findings.