Conducted 2 experiments with 12 paid female undergraduates and 26 undergraduates receiving course credit, respectively. The Ss judged the subjective worth of bets defined entirely by verbal phrases such as "somewhat unlikely to win sandals." A theory of information integration predicts that the subjective values of probability and payoff should combine by multiplying. Procedures from functional measurement were applied to test the model and to scale the subjective values of verbal probabilities and payoffs. Data from both experiments support the model. The Ss also judged 2-part bets such as "highly probable to win watch" and "toss-up to win bicycle." The theory predicts that the worths of the 2 parts should combine by adding. In both experiments, however, the judged worth of 2-part bets was less than the sum of the worths of the parts. This subadditivity effect was also found in reanalyses of earlier studies on commodity bundles. This raises serious questions about the traditional additive utility approach to risky decision making. (23 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved)