Windschitl, P. D., & Young, M. E. (2001). The influence of alternative outcomes on gut-level perceptions of certainty. Organizational Behavior and Human Decision Processes, 85, 109-134.

Recent research has demonstrated that the perceived certainty of a focal outcome depends not only on the overall amount of evidence supporting the alternatives to the focal outcome, but also on how that evidence is distributed across those alternatives (e.g., Windschitl & Wells, 1998). Three experiments replicated this alternative-outcomes effect across a variety of evidence distributions and investigated a heuristic comparison account for the effect. Participants provided gut-level certainty estimates for winning hypothetical raffles in which they and several other players held specified numbers of tickets. Results revealed that alternative-outcomes effects are not dependent on variations in the rank-order status of the focal outcome (Experiment 1) and are reliable but reduced in magnitude when the focal outcome is the least likely outcome (Experiment 2). Also, consistent with a core premise of the heuristic comparison account, evidence supporting the strongest alternative outcome was shown to play the primary role in producing alternative-outcomes effects (Experiment 3).