Moderated Mediation in AMOS

The series of tutorials from the very basic to the advance will help research scholar advance their knowledge in Moderated Mediation using SPSS AMOS.

Moderated Mediation

In more complex models, you may have a mediation model that also has a moderator on one of the indirect paths.
Not only are you trying to determine if mediation is present, but you are also trying to see if a moderator is changing the strength of the indirect effect.
The easiest way to tackle this issue is to use the estimands function in AMOS outlined in the mediation tutorial.
Let’s look at our moderation example again, only now we are going to examine if the moderator is influencing the indirect effect. Our simple mediation test will be if Organizational Commitment leads to Collaborative Culture, which leads to Organizational Performance.
Our moderator will be the construct of Role Ambiguity, which negatively influences the relationship from Organizational Commitment to Organizational Performance through Collaborative Culture. See the graphical representation that follows.

In AMOS, we drag in our constructs and include the paths for mediation. We also include the moderator and the interaction term into the model.
Note the interaction term needs to be created by the mean centered variables as outlined in the moderation examples presented earlier.
After we have drawn the model, we label all the parameter estimates. This will be necessary when we start using the estimands function in AMOS.

In the estimands function, we are going to examine the indirect effects at different levels of the moderator. In AMOS, we are going to select the “Define new estimands” function which will bring up a pop-up window.
The indirect effect is the product of the A_Path and the B_Path. Initially, we are going to tell AMOS to calculate the labeled parameter “A_Path” by the “B_Path”. This is going to determine the indirect effect in the presence of the moderator.
Make sure the moderator and interaction term are included in the model; we are not trying to piecemeal the analysis.
Next, we need to “probe” the indirect effect to determine how the moderator influences the indirect effect when it is at different levels.
In the estimands function, let’s label these tests “OneStandBelow” and “OneStandAbove”. This will denote that the moderator is one standard deviation below the mean and one standard deviation above the mean. The standard deviation for Role Ambiguity is 1.36595.

How to Test Moderated Mediation (Single Indirect Effect) – Part 1

How to Test Moderated Mediation (Part 2) – Multiple Indirect Effects

The session focuses on how to perform Moderated Mediation Analysis using SPSS AMOS. The model analyzed is similar to Hayes Process Macro Model 14.