When a data file includes a grouping variable, it is possible to use the SPSS Split File command (Data > Split File) to tell SPSS to rerun the same analysis on every group that is defined by the grouping variable. For instance, if you have data on job satisfaction for 400 employees in 20 work teams, you can tell SPSS to split the file by work teams and run the same analysis over and over for each of those 20 work teams. However, SPSS has different rules about how many categories your grouping variable can contain depending on whether its a string variable or a numeric variable. There is no limit to the number of categories your grouping variable can contain if the groups are coded with number and the variable is defined as a numeric variable In contrast, if the grouping variable is a string variable and the categories are coded with words or letters, SPSS limits the Split File command to only eight categories. Another great reason to avoid string variables in SPSS!