Psychology and neighboring disciplines are currently consumed with a replication crisis. Recent work has shown that replication can have the unintended consequence of perpetuating unwarranted conclusions when repeating an incorrect line of scientific reasoning from one study to another. This tutorial shows how decision researchers can derive logically coherent predictions from their theory by keeping track of the heterogeneity of preference the theory permits, rather than dismissing such heterogeneity as a nuisance. As an illustration, we reanalyze data of Barron and Ursino (2013). By keeping track of the heterogeneity of preferences permitted by Cumulative Prospect Theory, we show how the analysis and conclusions of Barron and Ursino (2013) change. This tutorial is intended as a blue-print for graduate student projects that dig deeply into the merits of prior studies and/or that supplement replication studies with a quality check.