The development of a deductive reasoning test: the construct structure and factors affecting the test item difficulty.

Abstract

In this study we discuss theoretical construct of deductive reasoning and propose test aimed at its evaluation. The theory of mental models and belief bias effect in logical reasoning were taken as conceptual framework.
In the first study the two-factor structure of the deductive reasoning construct was revealed. The two factors underlying the construct were the sequential reasoning and the analysis of alternatives. In the second study we cross-validated the two-factor structure and investigated the effect of mental models and belief bias on performance. 
We concluded that two scales of the deductive reasoning test can be used for measuring two independent skills of deductive reasoning – the sequential reasoning and the analysis of alternatives. Each scale showed good psychometric characteristics and clear structure. Validity of the test was supported by the concordance between the item difficulty from one hand and the number of mental models involved and item believability from another. Directions for further investigation are discussed.