By default answers are expected to be numeric values. You can change that to character with items.char=TRUE.
The parameter answ is quite versatile. You can just feed it your observation data,
      if it complies
with the naming scheme for items (Item###,
      see also klausur.gen), and
klausur.gen.corr will use all of its items automatically. Or you assign the number of items directly
as an integer value. If you leave answ=NULL,
      you will be asked for the number of items.