Talk:Mediation (statistics)

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This should be moved to Mediation (statistics). If no objections are raised within 24h or so, I'll move it. Jobjörn (Talk ° contribs) 21:55, 24 December 2006 (UTC)

This doesn't make any grammatical sense: "The inclusion of the mediating variable into the equation increases the relation between the treatment and outcome rather accounts for (decreases in terms of the size of the statistical relation)." I'm not sure what the author intended.

Would this be clearer? (Although, somewhat longer!)

"The inclusion of the mediating variable into the equation increases the significance of the relationship between the IV and DV. That is, the mediating variable can not explain or account for the variance in the DV itself, yet its inclusion in the equation increases the significance of the IV-DV relationship."

I'm still grappling with the idea of suppression, so if someone could confirm (and/or streamline!) the above, that'd be great! Skittled 00:16, 12 April 2007 (UTC)

[edit] Mediation (quantitative psychology)

This entry is written in the tradition of mediation as it exists within quantitative psychology. It is a good entry, but I don't think that the entry reflected that it was only concerned with a particular account of the concept of mediation. I feel that a proper place for this entry should be Mediation (quantative psychology) as the present entry does not say a whole lot about the statistical views on mediation (nothing on counterfactuals, graphical models, no mentioning of problems inherent in the extrapolation of the standard psych methods to non-linear models etc), but primarily deals with the statistics used my people with quantative psychology to quantify mediation. To my (limited) knowlegde there are seperate traditions of mediation in statistics, epidemiology and sociology, which are not covered by this entry.

--Udansk 09:06, 1 April 2007 (UTC)

I think the defintion of full vs. partial mediation should be reconsidered per Baron and Kenny (1986). Full or complete mediation occurs under the condition where the IV/DV relationship becomes zero (in contrast to when it becomes statisically no different than zero). Partial mediation occurs when the IV/DV relationship falls below significance when the mediator is included but the value of the coefficient between the IV and DV is not actually different. A potential mediator can be said to have no effect when the IV/DV relatioship is not reduced to non-significance. The way in which full and partial mediation is currently being defined creates a situation where considering a variable as a mediatior, this variable will almost always be labeled as either having a mediation effect or having a suppressive effect depending on it effect on the IV/DV relationship. However, these effects are likely to either be very small and/or, more importantly, unreliable. By the current standard it is almost never the case that a potential mediation has no effect on the IV/DV relationship whatsoever, it will almost always be labeled as a partial mediator or suppressor. I submit that this be changed and a more conservative view be taken whereby the occurance of full mediation (the actual reduction of the IV/DV relationship is reduced to zero or near zero) be the more rare occurance rather than the rare occurance be that potential mediatiors have no effect at all.

[edit] Yes it should be merged.

I think that this page should be merged because it is only a short page and could be easily merged.

Also, on the other page (Mediation (statistics)), there is a diagram showing a triangle with one of the points being "Mediator Variable" but there is no section about it in the page.

It would make much more sense to merge it into this page under a subsection (subheading) Mediator Variable.