Word Formation in Natural Language Processing Systems

Systems which process na tu ra l language requ i re a r e l i a b l e source of i n fo rmat ion about words. Not only must t h e i r l e x i c a l subsystems handle a large known words; they must a lso cope w i t h The morphological p r i n c i p l e s under l y ing "poss ib le word" are under ac t i ve study by l i n g u i s t s , and are a r t i c u l a t e d in the theory of word fo rmat ion . This paper presents a technique fo r b u i l d i n g l e x i c a l subsystems which embody these p r i n ­ c ip les by emulat ing the behavior of word format ion r u l e s . These subsystems combine t o t a l l y i d i o s y n ­ c r a t i c l e x i c a l i n f o r m a t i o n , s tored in a d i c t i o n a r y , w i t h systematic in fo rmat ion der ived from word s t r u c ­ t u r e . App l i ca t i ons fo r l e x i c a l subsystems b u i l t along the l ines descr ibed here w i l l be d iscussed.