The present article investigates the effectiveness of methods traditionally used to distinguish between the emotions of regret and disappointment and presents a new method — the Regret and Disappointment Scale (RDS) — for assessing the two emotions in decision making research. The validity of the RDS was tested in three studies. Study 1 used two scenarios, one prototypical of regret and the other of disappointment, to test and compare traditional methods with the RDS. Results showed that only the RDS clearly differentiated between the constructs of regret and disappointment. Study 2 confirmed the validity of the RDS in a real-life scenario. Study 3 showed the advantages of the RDS over the traditional methods in gambling situations commonly used in decision making research, and provided evidence for the convergent validity of the RDS.
