Windschitl, P. D., & Krizan, Z. (2005). Contingent approaches to making likelihood judgments about polychotomous cases: The influence of task factors. Journal of Behavioral Decision Making, 18, 281-303.

Two experiments tested the influence of three task factors on respondents' tendency to use normative, heuristic, and random approaches to making likelihood judgments about polychotomous cases (i.e., cases in which there is more than one alternative to a focal hypothesis). Participants estimated their likelihood of winning hypothetical raffles in which they and other players held various numbers of tickets. Responding on non-numeric scales (vs. numeric ones) and responding under time pressure (vs. self-paced) increased participants' use of a comparison-heuristic approach, resulting in non-normative judgment patterns. A manipulation of evidence representation (whether ticket quantities were represented by numbers or more graphically by bars) did not have reliably detectable effects on processing approaches to likelihood judgment. The authors discuss the implications of these findings for the further development of likelihood judgment theories, and they discuss parallels between contingent processing in choice and contingent processing in likelihood judgment.