Abstract: Regressive independence means that conditional expectation E(Y|X) of two random variables X and Y does not depend on X. The relation between regressive independence and random independence is discussed, and several necessary and sufficient conditions are presented.

Key words: Conditional expectation, random independence, weak association

摘要： 回归独立性是指给定随机变量X时，随机变量Y的条件期望E(Y|X)不依赖于X。本文讨论了回归独立性与随机独立性之间的关系，得到了两者等价的几个充分必要条件。并指出了这些条件在统计分析中的应用。

关键词: 条件期望, 随机独立性, 弱关联