Investigating graph similarity perception: a preliminary study and methodological challenges

Graphs have become an indispensable model for representing data in a multitude of domains, including biology, business, financing, and social network analysis. In many of these domains humans are repeatedly confronted with the need to visually compare node-link representations of graphs in order to identify their commonalities or differences. Yet, despite its importance little is known about how much visual differences affect users' perception of graph similarity. As a result, more systematic investigations addressing this issue are necessary. However, from a methodological point of view there are still many open questions regarding the investigation of graph comparisons. To this end, this paper provides an overview of methodological challenges, presents results of an explorative study conducted to identify individual factors influencing the recognition of graph differences, and discusses lessons learned from this study. Our considerations and results can serve as foundation for further studies in this area and can contribute to the comparability of these investigations.