Taxonomic and Ecological Relations in Open-ended Induction

Recent research suggests that inductive inference may be based on salient relations between premise and/or conclusion categories (Medin, Coley, Storms and Hayes, 2003). The types of relations deemed relevant may be influenced by experience (e.g. López, Atran, Coley, Medin and Smith, 1997; Shafto & Coley, 2003). Novices in a given domain have been shown to rely primarily on taxonomic relationships to guide their inductive inferences. In contrast, experts show flexible use of both taxonomic and non-taxonomic relations. Previous research has assessed induction using forced choice tasks or ratings of argument strength, measures that may underestimate the salience of non-taxonomic relations for novices. The present study investigated the use of taxonomic and non-taxonomic relations among novices in the domain of local animal species using an open-ended task. Participants were given 12 pairs of taxonomically or ecologically related animals both known to have a certain property and asked to list other animals that might also have that property. Results show that relations among premise pairs had systematic effects on open-ended inferences. Overall, responses based on ecological relations were more frequent than taxonomic responses for novices. These results suggest that given an open-ended task, novices do demonstrate sensitivity to relevant relations among premise categories in generating inductive inference.