Brian D. Hall | Searcharxiv

arXiv2022

The Risks of Ranking: Revisiting Graphical Perception to Model Individual Differences in Visualization Performance

Graphical perception studies typically measure visualization encoding effectiveness using the error of an "average observer", leading to canonical rankings of encodings for numerical attributes: e.g., position > area > angle > volume. Yet different people may vary in their ability to read different visualization types, leading to variance in this ranking across individuals not captured by population-level metrics using "average observer" models. One way we can bridge this gap is by recasting classic visual perception tasks as tools for assessing individual performance, in addition to overall visualization performance. In this paper we replicate and extend Cleveland and McGill's graphical comparison experiment using Bayesian multilevel regression, using these models to explore individual differences in visualization skill from multiple perspectives. The results from experiments and modeling indicate that some people show patterns of accuracy that credibly deviate from the canonical rankings of visualization effectiveness. We discuss implications of these findings, such as a need for new ways to communicate visualization effectiveness to designers, how patterns in individuals' responses may show systematic biases and strategies in visualization judgment, and how recasting classic visual perception tasks as tools for assessing individual performance may offer new ways to quantify aspects of visualization literacy. Experiment data, source code, and analysis scripts are available at the following repository: https://osf.io/8ub7t/?view\_only=9be4798797404a4397be3c6fc2a68cc0.

cs.HC↗

arXiv2022

Augmented Chironomia for Presenting Data to Remote Audiences

To facilitate engaging and nuanced conversations around data, we contribute a touchless approach to interacting directly with visualization in remote presentations. We combine dynamic charts overlaid on a presenter's webcam feed with continuous bimanual hand tracking, demonstrating interactions that highlight and manipulate chart elements appearing in the foreground. These interactions are simultaneously functional and deictic, and some allow for the addition of "rhetorical flourish", or expressive movement used when speaking about quantities, categories, and time intervals. We evaluated our approach in two studies with professionals who routinely deliver and attend presentations about data. The first study considered the presenter perspective, where 12 participants delivered presentations to a remote audience using a presentation environment incorporating our approach. The second study considered the audience experience of 17 participants who attended presentations supported by our environment. Finally, we reflect on observations from these studies and discuss related implications for engaging remote audiences in conversations about data.

cs.HC↗