中文摘要：

归纳推理研究中存在着一个非常重要的现象：前提数目的增加对归纳推理强度的影响，即单调性效应和非单调性效应。单调性效应和非单调性效应既是归纳推理理论模型的具体阐释，也是其理论基础和源泉。但是由于对归纳推理这个概念的界定不一以及归纳推理任务的选择标准不同，已有的许多研究并非标准的归纳推理研究，夹杂着其他如演绎推理、类比推理等心理成分，其研究结论值得商榷。采用标准的归纳推理任务研究结果表明，单调性效应与非单调性效应的出现同前提与结论之间的类属关系有关。

英文摘要：

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-monotonlc 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 inductive reasoning, and they combined with other mental dements such as deductive reasoning and analogy reasoning, therefore their results are worth further discussing. The experiment with standard inductive reasoning tasks shows that the occurring of monotonic effect or nonmonotonic effect depends on the category relation between premises and the conclusion.