
Jason T. Newsom PhD Professor, Department of Psychology,
Portland State University 

Current Courses Past Courses Resources Other 

Macros 
Simple1.sps
(SPSS for Windows, now works for all versions through SPSS 23) SPSS macro for
testing the interaction between two continuous variables and calculating simple
slopes. The macro centers two predictors for a twoway interaction, computes
the product term, runs a regression analysis to test the interaction,
calculates the correct standardized coefficient for the interaction,
calculates simple slopes at 1 SD, the mean, and +1SD, tests them for
significance, and plots them. Instructions on how to use it are contained in
a comment box at the beginning of the macro.
Instructions:
1. Download
the SPSS syntax file simple1.sps containing the macro and store it on your
hard drive. (You may open this file like any other syntax file and read the
instructions. The macro does not need to be open to use it, however).
2. Start a
syntax file or add to an existing one.
4. Open your
data file or add a get file command to access your data.
3. Create
three variables, x, z, and y from your existing variables via menus or syntax
as in the example below. The macro will test and plot simple slopes for x
predicting y at three values of z (1 SD below its mean, its mean, +1 SD above
its mean).
COMPUTE X=independent
variable name. COMPUTE Z=moderator
variable name. COMPUTE Y=dependent
variable name. 4. Add the
following three lines of syntax, filling in the desired locations on your computer.
Include covariates if desired. If not, just put a period after the equal
sign.
CD 'file
path for saving temporary files/'. INCLUDE 'file
path for macro/simple1.sps'. SIMPLE1 VARS=covariate
variable names if desired. 5. Highlight and run. Simple2.sps. (SPSS for Windows only, now
works for all versions through SPSS 23) An SPSS macro for testing the
interaction between a continuous and a dichotomous variable and calculating
simple slopes. This macro can be accessed with two simple lines in any syntax
file. It centers the continuous predictor for a twoway interaction, computes
the product term, runs a regression analysis to test the interaction,
calculates the correct standardized coefficient for the interaction,
calculates simple slopes at 0 and 1 of the moderator, tests them for
significance, plots them, and calculates DeShon and
Alexander's homogeneity ratio. Download the SPSS syntax file containing the
macro and store it on your hard drive. Instructions on how to use it are
contained in a comment box at the beginning of the macro. A few lines of
syntax are needed to call the macro and execute it.
Instructions:
1. Download
the SPSS syntax file simple2.sps containing the macro and store it on your
hard drive. (You may open this file like any other syntax file and read the
instructions. The macro does not need to be open to use it, however).
2. Start a
syntax file or add to an existing one.
4. Open your
data file or add a get file command to access your data.
3. Create
three variables, x, z, and y from your existing variables via menus or syntax
as in the example below. The macro will test and plot simple slopes for x
predicting y at two values of z. The moderated z must be coded 0 and 1.
COMPUTE X=independent
variable name. COMPUTE Z=moderator
variable name. COMPUTE Y=dependent
variable name. 4. Add the
following three lines of syntax, filling in the desired locations on your
computer. Include covariates if desired. If not, just put a period after the
equal sign. Note that file path for saving temporary files/ must be a
location you are authorized to save to on your computer.
CD 'file
path for saving temporary files/'. INCLUDE 'file
path for macro/simple1.sps'. SIMPLE2 VARS=covariate
variable names if desired. 