[...] new forms can be created either by analogy [Paul, H., 1886, “Prinzipien der Sprachgeschichte”, Halle, Newmeyer] or by rules (usually referred to as "redundancy rules", but also occasionally as "schemas"). The use of such rules or of analogy would constitute a "fall-back procedure".
- Stemberger & MacWhinney (2004a), a pag.87