Using Gap Charts to Visualize the Temporal Evolution of Ranks and Scores

To address the limitations of traditional line chart approaches, in particular rank charts (RCs) and score charts (SCs), a novel class of line charts called gap charts (GCs) show entries that are ranked over time according to a performance metric. The main advantages of GCs are that entries never overlap (only changes in rank generate limited overlap between time steps) and gaps between entries show the magnitude of their score difference. The authors evaluate the effectiveness of GCs for performing different types of tasks and find that they outperform standard time-dependent ranking visualizations for tasks that involve identifying and understanding evolutions in both ranks and scores. They also show that GCs are a generic and scalable class of line charts by applying them to a variety of different datasets.