Will Kirts and Lalo Munoz

 

When analyzing a data file in SPSS, all cases with valid values for the relevant variables are used. SPSS provides a function that allows us to separate a subset of cases within a data file.

 The Select Cases command prohibits from further analysis all those cases that do not meet specified selection criteria. 

 

We will introduce the Select Cases command by working through an example that involves the simplest selection standard, which is where we select cases that have a distinct value for a single existing variable.

 

For Example, suppose we have a data set from the Tour de France. This includes : The Year, Winner, Country of Origin, Time H.M.S., Average Speed km/h, Stages, Km Ridden, Starting Riders, and the Finishing Riders. (figure 1.) We want to be  able to narrow down the Tour de France data set to those cases just from, let's say, Stages 15. This is where Select Cases will help us.

(Fig. 1)

 

(Fig. 2) 

 

This helps us see the data in which we wanted to filter a lot more easier. And as you can see, there is a new variable, in the last column, that is labeled "filter_$". It demarcates the selected cases as 1's. If we do an analyzes on this data, it's only going to do it on those cases that correspond to Stage 15. As you can see it crosses out the Cases, on the left side, that are not associated with the number 15 on the variable we use, which is "Stages". (Fig. 2)

 

How to Select Cases in SPSS

• Go to "Data" menu and select "Select Cases"
• Once in the Dialog Box select "If Condition is satisfied" and then Click on "If..."
• In the source variable list, select the variable whose values will act as the filter. In this case it would be "Stages"
• Either Drag the Variable or click on the Arrow  to move it to the empty space.
• Once in the box, From the calculator pad or from the keyboard, type in the appropriate numbers. In the example we provides it'd be Stages=15, since it was the variable we would like to select. 
• Click "Continue".
• Then Click "OK"
• After clicking "OK", SPSS will create a new variable as the last column in the Data Editor labeled "filter_$".

 

 

The following video Illustrates these steps: