Judging relative duration: the role of rule and instructional variables

Humans compared 2 durations according to different rules. Some judged which duration lasted longer, some judged whether the duration ratio was less or greater than 3:1, and others judged according to a same-different rule. Under each condition, 1/2 of the participants had advance knowledge of the rule, whereas the others acquired the discrimination solely on the basis of informative feedback. Discrimination was affected by both factors. Same-different and ratio comparisons were less accurate than ordinal comparisons. Rule knowledge affected the ratio and same-different comparisons but did not affect judgment about which duration lasted longer. Debriefing of uninformed participants revealed that most guessed that the rule involved judging which duration lasted longer. These results highlight the role of linguistic variables in humans' relational comparisons of duration.