Proceedings of the Annual Meeting of the Cognitive Science Society

The present study examines whether peoples mental representation of discounted prices, which have a part-whole relation-ship of the current price to the original price, is similar to that of fractions. Participants performed a fraction comparisontask and a deal comparison task on the same set of fractional magnitudes. In two experiments, we observed worse perfor-mance (error rate, RT of correct trials) on the deal comparison task. The distance effect, where magnitude comparisons aremade more slowly and less accurately the closer two magnitudes are, observed in the two tasks was best modeled usinglogarithmic distance between the fractional magnitudes as a predictor of performance.