Note that in our example, we placed a numeric variable "Overall satisfaction with product" in the calculation area. If you attempt to drop a numeric question in a grouping panel area, the following prompt will appear.
Now, if you want to display the variable values as categories, click "OK." However, if you want the variable calculated as a mean or median, for example, place it in the other area or first change the calculation position.
IMPORTANT! The type of question (numeric / categorical) defines what kind of output style can be used for calculation. Read more in Question types and Selecting an output style.
It is also impossible to change the calculation position if it is currently set on a numeric variable.
Follow the prompt instructions i.e., convert the numeric variable into a categorical one ("Use as category variable"), and then change the calculation area.
The calculations are now being performed on the rows, where in our example the "Make of new car" variable is located, while the numeric variable is now treated as categorical.
Place the cursor over the blue triangle to make sure what calculations are being conducted in the column.
