4 10.1 Conceptual Dependency Conceptual Dependency is a theory of how to represent the kind of knowledge about events that is usually contained in natural language sentences. The goal is to represent the knowledge in way that - Facilitates drawing inferences from the sentences. - Is independent of the language in which the sentences were originally stated.
5 Conceptual Dependency A Simple Conceptual Dependency Representation “I gave the man a book.”
6 Conceptual Dependency Where the symbol have the following meanings : Arrows indicate direction of dependency. Double arrow indicates two way link between actor and action. p indicates past tense. ATRANS is one of the primitive acts used by the theory. It indicates transfer of possession. o indicates the object case relation. R indicates the recipient case relation.
7 Conceptual Dependency CD Primitive Actions ATRANSTransfer of an abstract relationship (e.g., give) PTRANSTransfer of the physical location of an object (e.g.,go) PROPELApplication of physical force to an object (e.g.,push) MOVEMovement of a body part by its owner (e.g.,kick) GRASPGrasping of an object by an actor (e.g.,clutch)
8 Conceptual Dependency INGESTIngestion of an object by an animal (e.g.,eat) EXPELExplusion of something from the body of an animal (e.g.,cry) MTRANSTransfer of mental information (e.g.,tell) MBUILDBuilding new information out of old (e.g.,decide) SPEAKProduction of sounds (e.g.,say) ATTENDFocusing of a sense organ toward a stimulus (e.g.,listen)
9 Conceptual Dependency CD Primitive Conceptual Categories ACTsActions PPSObjects (picture producers) AAsModifiers of actions (action aiders) AAsPAsModifiers of PPs (picture aiders)
10 Conceptual Dependency The Dependencies of CD
22 The Component of a Script Entry conditionsConditions that must, in general, be satisfied before the events described in the script can occur. ResultConditions that will, in general, be true after the events described in the script have occurred. PropsSlots representing objects that are involved in the event described in the script.
23 The Component of a Script RolesSlots representing people who are involved in the events described in the script. TrackThe specific variation on a more general pattern that is represented by the particular script. ScenesThe actual sequences of events that occur.
24 Triggering and Using Scripts Susan passed her favorite restaurant on her way to the museum. She really enjoyed the new Picasso exhibit. John went out to a restaurant last night. He ordered steak. When he paid for it, he noticed that he was running out of money. He hurried home since it had started to rain.
25 Triggering and Using Scripts Susan went out to lunch. She sat down at a table and called the waitress. The waitress brought her a menu and she ordered a hamburger. John went to a restaurant. He was shown to his table. He ordered a large steak. He sat there and waited for a long time. He got mad and left.
26 10.3. CYC CYC represent a specific theory of how to describe the world, and it can be used for AI tasks such as Natural Language Understanding CYC is more comprehensive CYC contain representations of event, objects, attitudes, and so forth.
27 CYC Motivations Reason to build large knowledge bases Brittleness Specialized knowledge based system are brittle Form an Content The technical we have seen so far for representing and using knowledge may or may not be sufficient for the purpose of AI. Shared Knowledge Small knowledge based system must make simplifying assumptions about how to represent thing like space, time, motion and structure.
28 CYC CYCL is CYC for representation language. CYCL is a frame-base system that incorporates most of the techniques described multiple inheritance. Control and Meta-Knowledge, where we saw how to take information about control out of a production system interpreter and represent in declaratively using rules. Global Ontology, that specifies at a very high level what kind of thing exist and what their general properties are. Tools, user’s modifications to the knowledge base are transmitted to a central server, where they are checked and then propagated to other users.