Hi all! I just added two new pages to MattCHoward.com for conducting statistics in Jamovi. The first covers mediation in Jamovi, whereas the second covers moderation in Jamovi. Links are below, and, as always, feel free to reach out if you have any questions. My email is MHoward@SouthAlabama.edu.
Recently, I performed a study in which I needed to test for dual mediation – when the
indirect effect of Y on X goes through two mediators
(pictured here). Whenever I need to test for mediation or moderation of any type, I first go to Hayes’s PROCESS macro for SPSS. It is easy, and it adheres to most all
current best-practices. If you don’t have it yet, I STRONGLY suggest that you download it now: http://www.processmacro.org/index.html . It has saved me hours (days?) on statistical analyses.
So, I opened up the documentation for PROCESS and I found…that it does not have a model for dual mediation! Of all things, I would have assumed that PROCESS would be able to test for dual mediation!
I searched online for solutions, and I even referred to mediation textbooks to
devise a formula to test for dual mediation. After having moderate success, I
finally went back to PROCESS. Out of frustration, I set the program to test the traditional mediation model (with one mediator), but I included two mediators in the dialogue window. And what did I see? It provided output for dual mediation!
While this information may not be groundbreaking, it certainly helped me. I hope that it can also help someone who is as frustrated with dual mediation as I was. The permanent page for dual mediation testing can be found here: Testing for Dual Mediation .
If you need any help running dual mediation in process (or any other statistical questions), feel free to email me at MHoward@SouthAlabama.edu. I always
enjoy hearing from people running interesting statistics!
I just uploaded a new page on the “Stats Help” portion of my website. The link is here: Sobel Test Formula for Serial Mediation / Sequential Mediation .
In short, I spent much too long finding the sobel test formula for the indirect effect of X on Y through M1 and M2 in a serial mediation / sequential mediation. To prevent this from happening to other researchers (and possibly myself again), I provide a brief summary of mediation, sobel tests, and serial mediation / sequential mediation. Then, I provide the relevant sobel test formula.
If you want to know more about serial mediation / sequential mediation, please contact me at firstname.lastname@example.org. I’m always happy to chat about stats!