Many-to-Many Geographically-Embedded Flow Visualisation: An Evaluation
This addresses a visualization challenge for researchers and practitioners dealing with geographic flow data, but it is incremental as it builds on existing methods like OD Maps.
The paper tackled the problem of visualizing dense many-to-many geographic flows by evaluating visual representations, finding that OD Maps and MapTrix performed similarly well, while bundled node-link flow maps did not scale effectively.
Showing flows of people and resources between multiple geographic locations is a challenging visualisation problem. We conducted two quantitative user studies to evaluate different visual representations for such dense many-to-many flows. In our first study we compared a bundled node-link flow map representation and OD Maps [37] with a new visualisation we call MapTrix. Like OD Maps, MapTrix overcomes the clutter associated with a traditional flow map while providing geographic embedding that is missing in standard OD matrix representations. We found that OD Maps and MapTrix had similar performance while bundled node-link flow map representations did not scale at all well. Our second study compared participant performance with OD Maps and MapTrix on larger data sets. Again performance was remarkably similar.