The best of times and the worst of times are interchangeable.

We commonly determine the most preferred (best) and least preferred (worst) of a set of options, yet it is unclear whether the 2 choices are based on the same or different information. We examined best and worst choices using discrete choice tasks, in which participants selected either the best option from a set, the worst option, or selected both the best and the worst options. One experiment used perceptual judgments of area, and another used consumer preferences for various attributes of mobile phones. In both domains, we found that the task (best, worst, or best and worst) does not alter the preferences expressed for the best (respectively, the worst) option. We also observed that the choice probabilities were consistent with a single latent dimension—options that were frequently selected as best were infrequently selected as worst, and vice versa—both within and between respondents. A quantitative model of choice and response time provided convergent evidence on those relations, with model variants that assumed an inverse relationship between the estimated parameters for best and worst choices accounting well for the data. We conclude that the diverse types of best and worst choices that we studied can be conceived as opposing ends of a single continuous dimension rather than distinct latent entities. We discuss these results in the light of rather different results