This tutorial shows how to do multiple linear regression in SPSS. Different from simple linear regression, multiple linear regression has more than 2 or more independent variables (i.e., multiple Xs).
In this tutorial, we test if students’ writing scores and math scores can be used to predict reading scores.
Read = b0 + b1 Write + b2 Math
Steps of Multiple Linear Regression in SPSS
Step 1: Select the menu of “Linear”
“Analyze”, then “Regression”, then “Linear.”
Step 2: Define variables
You can drag “read” as “Dependent” and “write” and “math” in “Block 1 of 1.” Then, you can hit OK to see the output.
Step 3: Interpret the output
The following is the key output of simple linear regression from SPSS.
The p-values for both “write” and “math” are < 0.001, which indicates that both of them are significant predictors. In other words, writing and math scores can be used as a predictor for reading scores.
We can also write out the model statement as follows, namely update the constant and regression coefficients. It means that, for writing scores to increase by 1 unit, reading scores will increase by 0.33 units. Further, for math scores to increase by 1 unit, reading scores will increase by 0.52 units.
Read = b0 + b1 Write + b2 Math = 7.54 + 0.33 Write + 0.52 Math
In addition, we can see that R2 is 0.496, which is greater than the R2 when it is a simple linear regression model that has only one predictor of write (0.356). For how to do simple linear regression, please refer to another tutorial.