Conceptual Dependency Theory

Schank and Students – 1968 Interlingua Form A Limited Set of Primitives Frame Based

Primitives PP - Picture Producers ACT – actions LOC - locations T - time PA - Attributes of PP

Conceptual Syntax

Physical ACTs PTRANS Propel Move Grasp Ingest Expel Speak physical Transfer occurs as an instrument Propel Move Grasp Ingest Expel Speak

Mental ACTs Mtrans Attend Mbuild

CD has Mental States MLOC – mental locations CP – conscious processor IM – intermediate memory LTM – long term memory

Social ACTs Atrans – abstract transfer

States Color(red) Height(6 feet) Health() Anger()

Micro ELI A CD analyzer

Input is (JACK WENT TO THE STORE) CD form is (PTRANS (ACTOR (PERSON (NAME (JACK)))) (OBJECT (PERSON (NAME (JACK)))) (TO (STORE)) ) This is a Frame: PTRANS Actor: Person name=Jack Object: Person name = Jack To: Store

Micro-ELI Internals ;;; ;;; Dictionary Functions (defmacro defword (&body def) `(progn (setf (get ',(car def) 'defintion) ',(cdr def)) ',(car def))) ;; Example vocabulary items... (defword jack ((assign *cd-form* '(person (name (jack))) *part-of-speech* 'noun-phrase)))

A CD form (defword went ((assign *part-of-speech* 'verb *cd-form* '(ptrans (actor ?go-var1) (object ?go-var1) (to ?go-var2) (from ?go-var3)) go-var1 *subject* go-var2 nil go-var3 nil) (next-packet ((test (equal *word* 'to)) ((test (equal *part-of-speech* 'noun-phrase)) (assign go-var2 *cd-form*)))) ((test (equal *word* 'home)) (assign go-var2 '(house))))))

Micro Tale spin Using: Build a story story representation World knowledge Build a story

A Story ; irving kills joe. (defvar *story2* '(irving thirsty (irving (like (actor joe) (to irving) (mode (neg)))) (irving (dominate (actor joe) (to irving) (mode (neg)))) (irving (deceive (actor joe) (to irving) (mode (pos)))) (irving (like (actor irving) (to joe) (mode (neg)))) (joe (deceive (actor irving) (to joe) (mode (neg))))))

The Output Once upon a time ... JOE WAS NEAR THE CAVE. JOE KNEW THAT JOE WAS NEAR THE CAVE. IRVING WAS NEAR THE OAK-TREE. IRVING KNEW THAT IRVING WAS NEAR THE OAK-TREE. JOE KNEW THAT IRVING WAS NEAR THE OAK-TREE. THE WATER WAS NEAR THE RIVER. JOE KNEW THAT THE WATER WAS NEAR THE RIVER. THE HONEY WAS NEAR THE ELM-TREE. IRVING KNEW THAT THE HONEY WAS NEAR THE ELM-TREE. THE WORM WAS NEAR THE GROUND. JOE KNEW THAT THE WORM WAS NEAR THE GROUND. IRVING KNEW THAT JOE WAS NEAR THE CAVE. THE FISH WAS NEAR THE RIVER. IRVING KNEW THAT THE FISH WAS NEAR THE RIVER. IRVING THOUGHT THAT JOE DID NOT LIKE IRVING. IRVING THOUGHT THAT JOE DID NOT DOMINATE IRVING. IRVING THOUGHT THAT JOE DECEIVED IRVING. IRVING THOUGHT THAT IRVING DID NOT LIKE JOE

JOE THOUGHT THAT IRVING DID NOT DECEIVE JOE. One day, IRVING WAS THIRSTY . IRVING WANTED NOT TO BE THIRSTY . IRVING WANTED TO BE NEAR THE WATER. IRVING WANTED TO KNOW WHERE THE WATER WAS . IRVING WANTED JOE TO TELL IRVING WHERE THE WATER WAS . IRVING WANTED JOE TO THINK THAT IF JOE WOULD NOT TELL IRVING WHERE THE WATER WAS THEN IRVING WOULD STRIKE JOE. IRVING WANTED TO BE NEAR JOE. IRVING WENT TO THE CAVE. IRVING WAS NEAR THE CAVE. IRVING TOLD JOE THAT IF JOE WOULD NOT TELL IRVING WHERE THE WATER WAS THEN IRVING WOULD STRIKE JOE. IRVING STRUCK JOE. JOE WAS NOT ALIVE . IRVING THOUGHT THAT JOE WOULD NOT TELL IRVING WHERE THE WATER WAS . IRVING THOUGHT THAT IRVING DID NOT KNOW WHERE THE WATER WAS . IRVING THOUGHT THAT IRVING WAS NOT NEAR THE WATER. IRVING KNEW THAT IRVING WOULD BE THIRSTY . The end.

World Knowledge ((world (loc (actor joe) (val cave))) (joe (loc (actor joe) (val cave))) (world (loc (actor irving) (val oak-tree))) (put 'joe 'is-a 'bear) (put 'joe 'home 'cave)

CD A critique Implicit relationships in world knowledge Ex hit implies touched Right primitives? Need higher level concepts for inference Semantic parsing didn’t pan out! Lexical structure adds detail! Just looking for slots was not good enough

CD final thoughts Without getting prescriptive CD can be used as a knowledge rep Needs extension in the CD Use more parsing