Interventions in Children's Deductive Reasoning with Indeterminate Problems

This study examined the effectiveness of three intervention measures designed to facilitate 10- and 12-year-old children's recognition of indeterminacy in reasoning with illogical syllogisms. The indeterminate nature of these syllogisms arises from the lack of logical connection between the premises, which means a single, logically correct solution cannot be drawn. The interventions addressed: (a) children's purported difficulties with closure, specifically, a lack of awareness and acceptability of indeterminate situations; (b) children's construction of complete mental models of the premise information; and (c) a combined approach, incorporating (a) and (b). The children brought a strong foundation of deductive processes to the study, which was necessary, but insufficient, for dealing with the indeterminate problems. Neither intervention (a) nor (b) alone, was adequate in developing children's ability to explicitly recognize indeterminacy; only the combined intervention made a significant difference. Possible reasons for this are explored, along with an analysis of children's difficulties in resolving these problems. A number of educational implications are also addressed.