I have done a couple of workshops on this topic.  Attached you will find some useful publications in case you need the citations.  Everyone and his tutor uses Baron and Kenny, for what its worth.

Dear Muhammad,

It might be worth revisiting the following similar question that was posed by Mahfuz Judeh on 23rd October 2013: “What is the difference in the role of moderator, and/or mediator”.

The following contributors, Boris F.Blumberg and Jos Akkermans provided detailed answers which can be found from the following link on researchgate:

https://www.researchgate.net/post/What_is_the_difference_in_the_role_of_moderator_and_or_mediator

Jos Akkerman further articulated the answer which I found very insightful with two links (in pictorial format) clearly demonstrating or highlighting the differences between  the two concepts.

I would certainly revisit the above link in response to your question.

Kind regards,

Nicholas

I have done a couple of workshops on this topic.  Attached you will find some useful publications in case you need the citations.  Everyone and his tutor uses Baron and Kenny, for what its worth.

From my viewpoint, a moderating relationship of variable z is the influence of variable x on y for different levels of z, whereas a mediating relationship is the effect of x on y through z. The Baron and Kenny paper suggested by Julia B. Smith is straightforward.

Regards,

Angel

Hi Muhammad,

Mediator variable is the middle variable / "middleman" between an independent variable (IV) and a dependent variable (DV). Objective of the mediator variable is to explain the relationship between IV & DV e.g. IV is not directly influencing DV but rather IV is indirectly influencing DV through mediator variable. Pictorially, Independent variable --> Mediator variable --> Dependent variable. For example, salary (IV) is positively influencing education (mediator variable) and then education is positively influencing health-screening expenses (DV). When the effect of education is removed, the relationship between salary and health-screening disappears.

Moderator variable is a third party variable that modify the relationship between an independent variable (IV) and a dependent variable (DV). Objective of the moderator variable is to measure the strength of the relationship between the IV & DV. Pictorially, moderator variable's arrow line is pointing to the mid point of the arrow-lined relationship between independent variable --> dependent variable. For example, if age is a moderator variable between salary (IV) and health-screening expenses (DV), then relationship between salary & health-screening can be stronger for older men and less strong for younger men.

Regards,

Fung

Baron & Kenny (1986) highlighted the importance of not using the terms moderator and mediator interchangeably.

Baron & Kenny (1986) wrote:

“The moderator function of third variables, which partitions a focal independent variable into subgroups that establish its domains of maximal effectiveness in regard to a given dependent variable. The mediator function of a third variable, which represents the generative mechanism through which the focal independent variable is able to influence the dependent variable of interest.”

Moderating Variable- moderator is a variable which will cancel the relationship with two variables. Moderator is a variable which will refuse the degree of relationship between two variables. Moderator can be totally canceled the relationship between two variables.

Moderating - changing

Eg: You feel sleep in the class after having a heavy lunch. So there is a relationship. But assume you don’t feel sleep in the class after having a huge lunch. The answer is the moderator, may be the interesting nature of the lecturer or exam fear.

Intervening variable alternatively called mediating variable

Intervening variable – Assume training and job performance, the relationship is positive. Greater the job training better the job performance. How does the training increase the job performance? If you have an answer, then the answer is the intervening variable. Learning is the acquisition of new knowledge and attitude. So training will result in learning which will result in job performance.

For more details please refer the articles given below.

References

Frazier, P.A., Tix, A.P. and Barron, K.E., 2004. Testing moderator and mediator effects in counseling psychology research. Journal of counseling psychology, 51(1), p.115.

Baron, R.M. and Kenny, D.A., 1986. The moderator–mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations. Journal of personality and social psychology, 51(6), p.1173.

@ Julia B. Smith

1. In my hypothesis, direct path is not significant but when I add Mediator(M) between Independent Variable(IV) and Dependent Variable(DV), path( IV> M and M> DV ) becomes significant. How can I describe this relationship. Is this relationship fully mediation or full indirect effect?

2. I have two mediators.What should I do? Can I add single mediator and testing the structure of relationship or add two mediators together and testing the structure of relationship?