Because simple mediation analysis is based on linear regression, you can obtain much of the necessary output from a simple mediation analysis using a linear regression routine in your favorite statistical software program. Of course, there is much more to mediation analysis than merely adding a variable to a regression model, and we will discuss some of those issues in this workshop. The second way is through M, the mediator. One way is direct, as in the simple regression model shown above. The idea is that X now has two ways to influence Y. In a simple mediation model, a third variable, called the mediator, M, is included in the model between X and Y. The understanding of the relationship between X and Y comes from a thorough understanding of how the data were collected. There is no way to know the nature of the relationship from just the statistical model. The relationship may be correlational or causal or something else. In this model, we assume that there is a relationship between the predictor variable X and the outcome variable Y. We will assume that everyone is familiar linear regression. Here is a conceptual diagram of a simple linear regression model: But conceptually, the mediator changes the simple regression model from a model that looks at the association of two variables to a model that tries to look at a causal relationship. Mathematically, the mediator acts like a covariate in the model. The difference between a simple linear regression and a simple mediation analysis is the inclusion of a single (continuous) mediator to the model. In a simple linear regression, we would have one continuous outcome and one predictor, perhaps a binary predictor or maybe a continuous predictor. Like so much in statistics, the basics of mediation models depend on a good understanding of linear (OLS) regression. Simple mediation model with continuous predictor The instructions describe the installation process of the custom dialog based on the version of SPSS you are running the execution of the process.sps file is the same in all versions of SPSS. The custom dialog will remain installed as you open and close the SPSS program, but you must run the process.sps file each time you open SPSS and want to use the PROCESS macro. Finally, open and run the process.sps file. Next, read the Installing PROCESS custom dialog PDF. Download the zipped file, and then unzip the file. First, go to and then to the Downloads tab (at the top of the page). Let’s take a moment to look at the installation process. Much of the material in this workshop is based on Introduction to Mediation, Moderation and Conditional Process Analysis: A Regression-based Approach, Third Edition by Andrew F. We will be using version 4.0 of the PROCESS macro. In this workshop, we will cover only some of what can be done with the PROCESS macro in SPSS.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |