Hierarchical classification as relational framing.

The purpose of this study was to model hierarchical classification as contextually controlled, generalized relational responding or relational framing. In Experiment 1, a training procedure involving nonarbitrarily related multidimensional stimuli was used to establish two arbitrary shapes as contextual cues for 'member of' and 'includes' relational responding, respectively. Subsequently those cues were used to establish a network of arbitrary stimuli in particular hierarchical relations with each other, and then test for derivation of further untrained hierarchical relations as well as for transformation of functions. Resultant patterns of relational framing showed properties of transitive class containment, asymmetrical class containment, and unilateral property induction, consistent with conceptions of hierarchical classification as described within the cognitive developmental literature. Experiment 2 extended the basic model by using "fuzzy category" stimuli and providing a better controlled test of transformation of functions. Limitations and future research directions are discussed.