Logical processing of set inclusion relations in meaningful text.

The present experiments attempted to resolve some recent conflicting findings in cognitive structure research between processing linear ordering and set inclusion relations described in meaningful paragraphs of text. In a self-paced study-test paradigm, college students studied such paragraphs. Definite processing differences were found for the two set-theoretic relations. Set inclusion test results were found to be due to faulty logical processing and not to memory retrieval problems. Subjects made invalid conversions of universally quantified statements and failed to make valid transitive inferences between such statements. This failure was found to be an increasing function of the distance separating the two terms in the set inclusion. No such problems were observed for linear orderings. The usual distance function was found: Accuracy on test questions about the ordering was an increasing function of the distance between the terms in the question. Results similar to those for linear orderings were observed for set inclusions when subjects were given special instructions about the validity and invalidity of symmetric and transitive inferences.