This dialogue is for Combining two columns in to one Columns to increase the amount of levels of a factor, and to delete a Column.
Combining 2 Columns
In this example Columns A and B are combined to double the amount of levels. Develve indicates that Column C will interact with this new column and is not usable anymore.
The result is that the combined column is stored in column A and Column B and C are deleted.
Changing columns
Add a extra Row.
An extra row can be easily added. But do this with care Develve indicates that the columns are unbalanced in this example. This is due to the fact that Level 2 is used 5 times and 1 only 4 times.