Click the ‘Save’ button and check the probabilities option to save the predicted
probabilities.
Click the ‘Options’ button to set the conditions for stepwise regression. In the ‘probability
for stepwise’ section you can indicate the significance values for Entry and Removal
during the stepwise procedure. For large data sets these values can be set at
respectively 0.01 and 0.02.
Run the regression by clicking ‘OK’.
Output will be generated in a special window. Use the help function if you have problems
interpreting the output.
Figure 19. Output section of the logistic regression with SPSS
The ‘Variable in the equation’ table in the ‘Block 1’ output section contains the resulting
logit model (Figure 19). The β values for the driving factors are the values in the column
B for the last step, in the example of Figure 14 the β value for population density
(POPDENS) is 0.001. By default only 3 decimals are shown, this number can be
increased in the Cell properties window. Select the specific cells and go to ‘Format | Cell
Properties’.