Merging Categories and Creating NETs
The table on the left shows the proportion of people to select each age category in a survey. Often it is useful to merge categories together. The table on the middle shows merged categories. The table on the right shows NETs, which are essentially merged categories that are shown in addition to the existing categories. Merging and the creation of NETs is widespread in survey analysis as it simplifies the data and the simpler the data the easier it is to interpret.
Some programs, such as Q and DataCracker, allow you to modify the data so that whenever you create tables the merging and netting of categories is remembered. Other programs, such as SPSS Custom Tables, Survey Reporter and MarketSight, work by letting you create new combined categories at the time of creating crosstabs, while others require you to instead create new categories as new variables by recoding existing variables (e.g., SPSS, R).