Observations of textual document management by individuals and organizations have suggested the popularity of using categories (e.g., folders) to organize, archive and access documents. The document grouping behavior is intentional acts, reflecting a user¡¦s preferential perspective on semantic coherency or relevant groupings between subjects. Although becoming less adequate as new documents are accumulated, the existing category set or hierarchy may preserve to some extent the user¡¦s preferential perspective on document grouping. Thus, when deriving a new category set or hierarchy, the category set or hierarchy previously established by the user (i.e., semantic coherency of the documents embedded in the existing category set or category hierarchy) should be taken into consideration. In this study, we have proposed an evolution-based technique, Category Hierarchy Evolution (CHE), for managing category hierarchy rather than category set. Specifically, in CHE, the overall similarity between two documents is measured not only by their content similarity but also by their location similarity in the existing category hierarchy. Our empirical evaluation results suggest that the proposed CHE technique outperformed the discovery-based technique (i.e., the traditional content-based document-clustering technique).

This investigation evaluated the use of conditional discrimination (CD) instruction and multiple exemplar instruction (MEI) to establish derived relational responding in accordance with hierarchical frames with school aged children. The first experiment used a multiple probe design to evaluate the effectiveness of MEI to teach participants to correctly respond to BELONGS TO and INCLUDES relations between academically relevant stimuli in the target hierarchy. The protocol was presented via an automated computer program. Written and oral intraverbal pre and posttest were administered to determine if CD instruction and MEI were sufficient for academically relevant behaviors to emerge. Transformation of stimulus functions was assessed using a property inheritance task. A retrospective protocol analysis was used to evaluate the covert verbal behavior the participants were engaging in when responding to the CD across the hierarchy task. The second experiment also used a multiple probe across participants design to assess hierarchical responding. An ABABCB withdrawal design was used to assess the functional relation of covert verbal behavior and the CD across the hierarchy task. The target stimuli and procedures for Experiment 2 were identical to the first experiment with the exception of using a concurrent protocol analysis as opposed to the retrospective protocol analysis to assess the role of the participants' covert verbal behavior on task performance. That is, the second experiment used the silent dog method (Hayes, White, & Bissett, 1998) to assess if self-talk is functionally related to the transformation of stimulus function task.