Predicting group decisions under uncertainty requires disentangling individual members' utilities over the consequences of choice, their expectations for uncertain outcomes, and their choice process as a group. I estimate simple Bayesian models of child-parent choice of high school track with subjective risk and unilateral or bilateral, nonstrategic decisions, by combining families' actual choices with novel survey information about children's and parents' subjective probabilities over choice consequences, their individually preferred choices, and their decision roles. A set of policy counterfactuals confirms the importance of introducing the beliefs and decision roles of individual members in models and policy analysis of group decisions.