潇湘渌水 @ 2010-06-29 14:14
中介变量必须满足三个条件：
(a) variations in levels of the IV significantly account for the variations in the presumed mediator (Figure 1),
(b) variations in the MV significantly account for variations in the DV, and
(c) when both IV and MV appear in the model, a previously significant relation between the IV and DV is no longer significant, with the strongest demonstration of mediation occurring when the direct IV to DV path is zero (Figure 2).
(a) variations in levels of the IV significantly account for the variations in the presumed mediator (Figure 1),
(b) variations in the MV significantly account for variations in the DV, and
(c) when both IV and MV appear in the model, a previously significant relation between the IV and DV is no longer significant, with the strongest demonstration of mediation occurring when the direct IV to DV path is zero (Figure 2).
调节变量moderator在moderation关系测试中，将IV，Moderator，IV x Moderator（乘积）都放到回归中，只要乘积显著就可以。我记得woodridge的计量书里也有类似的检测，当时好像没提是涉及 moderation调节关系的，忘记是哪一节涉及变量间乘积了。
再有一点，moderation一般是因为一些特殊因素（e.g.外部影响context information）在影响着IV和DV。
再有一点，moderation一般是因为一些特殊因素（e.g.外部影响context information）在影响着IV和DV。
