Slot and Filler structures

1. Strong slot and filler structures
• Weak slot and filler structures are very general
• There were no hard rules about what kinds of objects
and links are good in general for knowledge
representation.
The above can overcome by following strong slot and filler
structures
Conceptual Dependency
Scripts
CYC

2. Conceptual Dependency (CD):
• 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 a way that
• Facilitates drawing inferences from the sentences
• Is independent of the language in which the sentences were
originally stated.

3. Conceptual Dependency (CD):
• Conceptual Dependency is a high level strong filler structure
which is used to represent high level complicated knowledge
which requires solving complicated problems.
• CD is collection of symbols which are used to represent
knowledge.
• CD is the graphical presentation of high level knowledge.
• CD is a theory of how to represent the kind of natural about
events that is usually contained in natural language sentences.

4. Various Primitives (Symbols) used in CD
The set of primitive actions in CD, proposed by Schank and Abelson, is
presented below
1. ATRANS: - Transfer of an abstract entity (e.g. Give)
2. PTRANS: - Transfer of an physical location of an object (Go)
3. PROPEL:- application of physical force to an object (Push)
4. MOVE:- movement of body part by it’s owner (Kick)
5. GRASP: - Grasping or holding the object tightly by an actor (Clutch )
6. INGEST: - Ingestion of an object by an animal (eat)
7. XPEL:- expulsion of something from the body of animal (Cry, sweat)
8. MTRANS: - transfer of an mental information (Tell)
9. MBUILD:- Building a new information out of old (Decide)
10. SPEAK: - Production of sound
11. ATTEND: - Focusing of a sense organ towards a stimulus (listen)

5. Four primitive conceptual categories
from which dependency structures can
be built
• ACTs – Actions
• PPs – Objects (picture producers)
ex: Car, gravity
• AAs -- Modifiers(attributes) of actions (action aiders)
• Ex: “quickly” is AA in “he quickly run”
• PAs -- Modifiers of PPs (picture aiders)
• Ex: “blue” is PA in “ a blue car”
• T --- Times
• LOC -- Locations

6. Letters on Arrows
• o – object
• R – recipient donor
• I – Instrument (eat with a spoon)
• D – Destination (going home)

7. I gave the man a book

9. Set of Conceptual Tenses
•

10. Since smoking can kill you I stopped

11. Advantages
• Fewer inference rules are needed than would be required if
knowledge were not broken down into primitives
• Many inferences are already contained in the representation
itself
• The initial structure that is built to represent the information
contained in one sentence will have holes that need to be
filled. These holes can serve as an attention focuser for the
program that must understand ensuing sentences.

12. Scripts
• Script (1977):- (Schank and Abelson, 1977). Script is a
structure which is used to represent the knowledge .
• Script is a structure that describe a sequence of events in
particular context
• scripts are frame like structures used to represent
commonly occurring experiences such as going to
movies, shopping in supermarket, eating in restaurant,
banking.
• A script consist set of slots and information (knowledge)
contained in it

13. Various components of Script
are
• Script Name: - Title
• Track: - Special situation, specific variation
• Roles:- peoples involve in the event described in script
• Entry condition: - required pre situation to execute the
script
• Props: - non live object involve in the Script
• Scenes: - The actual sequence of events that occur
• Result: - Condition that will be True after events
described in the script are occurred

16. Scripts are useful
• The events described in a script form a giant causal chain.
• If a particular script is known to be appropriate in a given
situation then it can be very useful in predicting the
occurrence of events that were not explicitly mentioned.
• Scripts indicates how events which are mentioned relate to
each other.
• Before a particular script can be applied it must be activated.
Fleeting scripts
Non fleeting scripts

17. End
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