You can use the IBM SPSS Split File feature to split your data pond into separate groups for further analysis –based on the values of one or more grouping variables.
If you select multiple grouping variables, cases are grouped by each variable within categories of the preceding variable on the Groups Based On list.
For example, if you selected gender as the first grouping variable and minority as the second grouping variable, your cases will be grouped by minority classification within each gender category.
Good to know:
• You can specify up to eight grouping variables.
• Each eight bytes of a long string variable (string variables longer than eight bytes) counts as a variable toward the limit of eight grouping variables.
• Cases should be sorted by values of the grouping variables and in the same order that variables are listed in the Groups Based On list. If the data file isn’t already sorted, select Sort the file by grouping variables.
In my data pond, I have variables defined indicating marital status (a 0 or a 1) and retired indicator (again, a 0 or a 1). Using SPSS’s “split file” I chose “Organize output by groups”, selected my 2 variables (Marital status and Retired) as “Groups Based on” and then indicated “Sort the file by grouping variables”:
When I click the OK button, my result is a file into 2 “split files” – single people sorted by their retirement status and married people sorted by their retirement status.
Comparing Your Groups
These “split-files” are really groups (not physically separate files) and are presented together for comparison purposes. But all results from any procedures are displayed separately for each split-file group!
Pivot Tables
A single pivot table is created and each split-file variable can be moved between table dimensions.
Charts
A separate chart is created for each split-file group and the charts are displayed together in the Viewer.
Organizing Your Output Using Groups.
to split a data pond for analysis:
From the menus you choose:
1. Data > Split File…
2. Select Compare groups or Organize output by groups.
3. Select one or more grouping variables.
Remember! If your data isn’t already sorted by values of the grouping variables you’ll need to select Sort the file by grouping variables!
