T h e m a j o r f e a t u r e is that, in a d d i t i o n to conventional u s e r -d i r e c t e d p r o c e s s e s , there are a l s o c o m p u t e r -d i r e c t e d p r o c e s s e s , d i r e c t e d by a Computer-Directed P r o c e s s M a n a g e r (CDPM). For a C D P M t o f u n c t i o n , the s y s t e m must m a i n t a i n a c o n t i n u a l l yu p d a t e d m o d e l of t h e u s e r . T h e input to t h i s m o d e l is a h i s t o r y o f t h e p r o c e s s , g a t h e r e d by the History R e c o r d e r c o m p o n e n t of t h e s y s t e m , and analyzed by a H i s t o r y I n f e r e n c e P r o c e s s o r . S c h e m a theory p r o v i d e s a f r a m e w o r k for c o n s t r u c t i o n o f t h e m o d e l of the user and the C D P M .