Creating bands
Sometimes you may want to group the values in a numeric variable into categories. The process of creating categories from a numeric variable is sometimes called banding and each category is called a band. For example, the numeric visits variable in the Museum survey stores the number of times respondents have visited the museum before. Responses can contain any value from 1 to 100. To display this information on a table, you can specify a number of bands, and display one row or column for all responses that fall into each band.
You can use the Insert Bands dialog box to create automatic bands (for example, ten equal bands starting at the minimum value and ending at the maximum value) or you can define the bands individually.
To create bands
1 In the Variables pane, select the numeric variable for which you want to create the bands.
2 From the menu, choose Variables > Edit Variable.
This opens the Insert Bands dialog box, with the Edit Variable dialog behind it.
To create bands based on actual data values
1 In the Insert Bands dialog box, click Get values from data. The minimum and maximum values from the saved data are displayed in the From and To text boxes.
2 Click OK.
To create a number of equal bands
1 In the Insert Bands dialog box, enter the starting value for the first band in the From text box.
2 Enter the ending value for the final band in the To box.
3 Enter the number of bands to create in the Number of bands box.
4 If the variable contains responses that use decimals, use Number of decimals to set the number of decimal places to use for the bands.
5 Click OK to close the dialog box, and then click OK in the Edit Variable dialog box to save your changes.
To create single bands individually
1 In the Insert Bands dialog box, enter the starting and ending value for the first band in the From and To text boxes.
2 Set the Number of bands to 1.
3 If it is a real numeric variable, enter the Number of decimals.
4 Click OK.
5 Repeat as necessary for each band you want to create.
6 Choose Save and Close from the toolbar.
See also