In psychology, the take-the-best heuristic is a heuristic (a simple strategy for decision-making) which decides between two alternatives by choosing based on the first cue that discriminates them, where cues are ordered by cue validity (highest to lowest). In the original formulation, the cues were assumed to have binary values (yes or no) or have an unknown value. The logic of the heuristic is that it bases its choice on the best cue (reason) only and ignores the rest. Psychologists Gerd Gigerenzer and Daniel Goldstein discovered that the heuristic did surprisingly well at making accurate inferences in real-world environments, such as inferring which of two cities is larger. The heuristic has since been modified and applied to domains from medicine, artificial intelligence, and political forecasting. It has also been shown that the heuristic can accurately model how experts, such as airport customs officers and professional burglars, make decisions. The heuristic can also predict details of the cognitive process, such as number of cues used and response times, often better than complex models that integrate all available cues; as such, it is an example of the less-is-more effect. One-reason decision-making Theories of decision making typically assume that all relevant reasons (features or cues) are searched and integrated into a final decision. Yet under uncertainty (as opposed to risk), the relevant cues are typically not all known, nor are their precise weights and the correlations between cues. In these situations, relying only on the best cue available may be a reasonable alternative that allows for fast, frugal, and accurate decisions. This is the logic of a class of heuristics known as “one-reason decision making,” which includes take-the-best. Consider cues with binary values (0, 1), where 1 indicates the cue value that is associated with a higher criterion value. The task is to infer which of two alternatives has the higher criterion value. An example is which of two NBA teams will win the game, based on cues such as home match and who won the last match. The take-the-best heuristic entails three steps to make such an inference: Search rule: Look through cues in the order of their validity. Stopping rule: Stop search when the first cue is found where the values of the two alternatives differ. Decision rule: Predict that the alternative with the higher cue value has the higher value on the outcome variable. The validity v of a cue