Suppose that you want to run a regression model and to test the statistical
significance of a group of variables. For example, let’s say that you want
to predict students’ writing score from their reading, math and science
scores. The data set with these variables in it can be downloaded by
following this link:
hsb2.sav
.
The SPSS syntax for this would be:
regression
/dependent = write
/method = enter read math science.
Variables Entered/Removed(b)
Model
Variables Entered
Variables Removed
Method
1
science score, reading score, math score(a)
.
Enter
a All requested variables entered.
b Dependent Variable: writing score
Model Summary
Model
R
R Square
Adjusted R Square
Std. Error of the Estimate
1
.684(a)
.467
.459
6.97111
a Predictors: (Constant), science score, reading score, math score
ANOVA(b)
Model
Sum of Squares
df
Mean Square
F
Sig.
1
Regression
8353.990
3
2784.663
57.302
.000(a)
Residual
9524.885
196
48.596
Total
17878.875
199
a Predictors: (Constant), science score, reading score, math score
b Dependent Variable: writing score
Coefficients(a)
Unstandardized Coefficients
Standardized Coefficients
t
Sig.
Model
B
Std. Error
Beta
1
(Constant)
13.192
3.069
4.299
.000
reading score
.236
.069
.255
3.410
.001
math score
.319
.076
.316
4.222
.000
science score
.202
.069
.211
2.918
.004
a Dependent Variable: writing score
Now let’s suppose that you wanted to test the combined effect of math and
science on writing. The SPSS syntax for doing that is below. Note that the variables listed in the
method = test()
subcommand are not listed on the method = enter subcommand. In other
words, the independent variables are listed only once. Also note that,
unlike other SPSS subcommands, you can have multiple method =
subcommands within the regression command.
regression
/dependent = write
/method = enter read
/method = test(math science).
Variables Entered/Removed(b)
Model
Variables Entered
Variables Removed
Method
1
reading score(a)
.
Enter
2
science score, math score
.
Test
a All requested variables entered.
b Dependent Variable: writing score
Model Summary
Model
R
R Square
Adjusted R Square
Std. Error of the Estimate
1
.597(a)
.356
.353
7.62487
2
.684(b)
.467
.459
6.97111
a Predictors: (Constant), reading score
b Predictors: (Constant), reading score, science score, math score
ANOVA(d)
Model
Sum of Squares
df
Mean Square
F
Sig.
R Square Change
1
Regression
6367.421
1
6367.421
109.521
.000(a)
Residual
11511.454
198
58.139
Total
17878.875
199
2
Subset Tests
math score, science score
1986.569
2
993.284
20.439
.000(b)
.111
Regression
8353.990
3
2784.663
57.302
.000(c)
Residual
9524.885
196
48.596
Total
17878.875
199
a Predictors: (Constant), reading score
b Tested against the full model.
c Predictors in the Full Model: (Constant), reading score, science score, math score.
d Dependent Variable: writing score
Coefficients(a)
Unstandardized Coefficients
Standardized Coefficients
t
Sig.
Model
B
Std. Error
Beta
1
(Constant)
23.959
2.806
8.539
.000
reading score
.552
.053
.597
10.465
.000
2
(Constant)
13.192
3.069
4.299
.000
reading score
.236
.069
.255
3.410
.001
math score
.319
.076
.316
4.222
.000
science score
.202
.069
.211
2.918
.004
a Dependent Variable: writing score
Excluded Variables(b)
Beta In
t
Sig.
Partial Correlation
Collinearity Statistics
Model
Tolerance
1
math score
.396(a)
5.583
.000
.370
.561
science score
.322(a)
4.609
.000
.312
.603
a Predictors in the Model: (Constant), reading score
b Dependent Variable: writing score
If you wanted to test all three variables together, the syntax would be:
regression
/dependent = write
/method = test(read math science).
Variables Entered/Removed(a)
Model
Variables Entered
Variables Removed
Method
1
science score, reading score, math score
.
Test
a Dependent Variable: writing score
Model Summary
Model
R
R Square
Adjusted R Square
Std. Error of the Estimate
1
.684(a)
.467
.459
6.97111
a Predictors: (Constant), science score, reading score, math score
ANOVA(c)
Model
Sum of Squares
df
Mean Square
F
Sig.
R Square Change
1
Subset Tests
reading score, math score, science score
8353.990
3
2784.663
57.302
.000(a)
.467
Regression
8353.990
3
2784.663
57.302
.000(b)
Residual
9524.885
196
48.596
Total
17878.875
199
a Tested against the full model.
b Predictors in the Full Model: (Constant), science score, reading score, math score.
c Dependent Variable: writing score
Coefficients(a)
Unstandardized Coefficients
Standardized Coefficients
t
Sig.
Model
B
Std. Error
Beta
1
(Constant)
13.192
3.069
4.299
.000
reading score
.236
.069
.255
3.410
.001
math score
.319
.076
.316
4.222
.000
science score
.202
.069
.211
2.918
.004
a Dependent Variable: writing score
You will notice that the output from the first example with the three
independent variables on the method = enter subcommand and the output
from this example with the three independent variables on the method =
test() subcommand are virtually identical. The only difference between
them is the line in the ANOVA table that gives the test of the subset, which in
this case is all of the variables. The point of this example is that you
can put all of the independent variables in the regression on the method =
test() subcommand and not use a method = enter subcommand if you like.