Selecting cases for analysis in SPSS
When the researcher needs to perform selective analysis (for example, your research aim is to find out gender-based preferences for Lux soap. After you finish your survey, you may choose to do 2 separate analyses in SPSS: first of all males, then of all female respondents), then this command is used, i.e. selecting cases for analysis.
A practical example in SPSS
Consider that you want to examine gender differences in the adoption of construction technologies within firms. In order to do so, we need to click on “Data” on the Toolbar, and then click on Select cases (See Figure 1a).
After choosing select cases (Figure 1a), under “Select”, tick on “if the condition is satisfied” and also click on the “if” tab (See Figure 1b above).
This will take you to a dialogue box (See Figure 2) that allows you to complete the command necessary to carry out the procedure. Considering the example, that I gave you, Males are coded 1 and Females are coded 2 (I gave these codes in the Variable View sheet of SPSS). I am interested in calculating results separately for both groups. Therefore, I click on “Gender” under the variable list (see fig. 2) and use the arrow to put it in the box allocated for formulas. Once this variable has been transferred, I click on the = sign on the calculator provided and then on a “1” so that I inform the computer that I am only interested in selecting cases for males.
Figure 3 window will open after u clicked on “Continue” i.e. the original select cases dialogue box where you must choose any ONE: “Filter out Unselected Cases” OR “Delete Unselected Cases”. If you wish to keep both males and females in the dataset, but you want to conduct separate analyses for each group, you have to choose “Filter out Unselected Cases.” If you wish to get rid of those cases that don’t meet the criterion, i.e. you want to delete the females from the data set permanently, you will have to choose “Delete Unselected Cases” (See Figure 3 below).
Warning: Once you select “Delete Unselected cases” for any variable then you will not be able to perform any further tests on that variable. Therefore it is advised to avoid choosing this option (“Delete unselected cases”).
So, next, when we will conduct the analysis using Cross tabulations, we would get the results with respect to only Males (See Figure 4).