Effects of instructing the relevance and processing efforts on property induction

Medin et al (2003) proposed that relevance is crucial for property induction. Two experiments were conducted to test the effects of instructing the relevance and processing efforts. In both experiments, the relevance of causality or the diversity was manipulated by giving different instructions. Processing efforts were manipulated differently in the two experiments. In Experiment 1, processing effort was manipulated by setting time limits. Giving instruction about the relevance did not affect performance when participants had to answer in less than four seconds. However, instructing the relevance of causality increased the believability of the conclusion when participants were allowed to respond in 10 seconds. In Experiment 2, two premises and the conclusion were presented either simultaneously or successively. Instructing the relevance of diversity or causality increased the believability of the conclusion when the two premises and the conclusion were presented successively. The results gave partial support for the relevance theory.