Abstract: There is a very important phenomenon in the researches on inductive reasoning: the number of premises has a great influence on inductive strength,called monotonic effect or non-monotonic effect.Monotonic effect and non-monotonic effect are both the explanations and theoretical sources of the models of inductive reasoning.However,because the defining about the concept of inductive reasoning is not unity and the standard for choosing inductive reasoning tasks is different,previous researches are not standard ...