Mixed Uncertainty in One View: Co-Visualizing Statistical Variability and Qualitative Confidence

Authors

Racquel Fygenson (Northeastern University), Lace M. Padilla (Northeastern University), Laura Matzen (Sandia National Laboratories)

Presentation

Session
I'm not so certain
Time
Thursday, Nov 12, 08:12 – 08:24 (US/Eastern) · session 08:00 – 09:30
Location
Hall Essex north

Keywords

data visualization, time series, qualitative confidence, forecast visualization, forecast uncertainty

Abstract

Forecasting involves multiple forms of uncertainty, including both uncertainties that can be quantified directly (quantitative uncertainty) and those that must be expressed through experts’ subjective judgments about the forecast and its context (qualitative confidence). Past work has established that conveying both quantitative uncertainty and qualitative confidence in forecasts can alter readers’ decision making, but little research investigates the impact of how these forms of uncertainty are presented. In this work, we present three preregistered human-subjects studies (total n = 923) on how different methods of visualizing qualitative uncertainty alongside line charts' confidence intervals affects non-experts' decision making. In particular, we investigate representing qualitative uncertainty separately via text and icons, and integrated into quantitative confidence intervals via color, transparency, and a blurred stroke design. In Experiment 1, we confirm that showing qualitative confidence alongside statistical variability can change patterns of decision making, replicating findings from previous work in the new context of time-series line charts. In Experiments 2 and 3, we find several non-textual encoding techniques that produce similar effects in participants' incorporation of qualitative confidence into their judgments. Our findings suggest actionable guidelines for visualization designers who seek to represent multiple forms of uncertainty for a single line chart forecast. A free copy of this paper and all supplemental materials are available at https://osf.io/7ya2c/overview.

For Practitioners

This paper is relevant to even forecasters and public safety communicators who want to better communicate uncertainty, especially uncertainty that comes in multiple forms. This paper advises on novel methods for communicating both quantitative uncertainty and qualitative confidence, as well as these methods impact on forecast readers' decision making.