Representations of Knowledge in a Program for Solving Physics Problems

A computer p rogram w h i c h s o l v e s p h y s i c s p r o b lems s t a t e d i n E n g l i s h i s d e s c r i b e d i n terms o f t h e knowledge w h i c h i s used t o t r a n s f o r m one t y p e o f r e p r e s e n t a t i o n i n t o a n o t h e r . The E n g l i s h s e n t e n c e s o f t h e p r o b l e m s t a t e m e n t a re p r o g r e s s i v e l y t r a n s f o r m e d i n t o a s e m a n t i c n e t w o r k f o r m , a l a n g u a g e f r e e i n t e r n a l model o f t h e o b j e c t s i n t h e p r o b l e m and t h e i r a t t r i b u t e s and r e l a t i o n s h i p s , a s e t o f c a n o n i c a l o b j e c t f rames w h i c h i n t e r p r e t a c t u a l o b j e c t s as c a n o n i c a l o b j e c t s (such as a p o i n t mass) , a g e o m e t r i c m o d e l , a s e t of equat ions , and a p i c t u r e m o d e l . The g e n e r a l n o t i o n o f a c a n o n i c a l o b j e c t f r a m e , w h i c h a b s t r a c t s a s u b s e t o f t h e p r o p e r t i e s o f a n o b j e c t t o f o rm a r e p r e s e n t a t i o n o f a c a n o n i c a l o b j e c t whose i n t e r a c t i o n s w i t h r e l a t e d c a n o n i c a l o b j e c t s can b e f o r m a l l y m o d e l l e d , i s d i s c u s s e d as a method o f o r g a n i z i n g p r o b l e m s o l v i n g p r o g r a m s .