  Data visualizations are standard tools for assessing and communicating risks.
However, it is not always clear which designs are optimal or how encoding
choices might influence risk perception and decision-making. In this paper, we
report the findings of a large-scale gambling game that immersed participants
in an environment where their actions impacted their bonuses. Participants
chose to either enter a lottery or receive guaranteed monetary gains based on
five common visualization designs. By measuring risk perception and observing
decision-making, we showed that icon arrays tended to elicit economically sound
behavior. We also found that people were more likely to gamble when presented
area proportioned triangle and circle designs. Using our results, we model risk
perception and discuss how our findings can improve visualization selection.
