Q20Principles of Artificial Intelligence

To execute intelligent actions, an AI must mathematically map the chaotic physical universe into its RAM. Knowledge Representation (KR) architectures define the exact mathematical data structures used to store facts, constraints, and relationships.

The absolute most rigorous mathematical architecture. It utilizes strict Boolean logic and quantifiers.

• Mechanism: It uses predicates, variables, Universal Quantifiers ($\forall$), and Existential Quantifiers ($\exists$).
• Example: To represent "All dogs are mammals": $\forall x(Dog(x)\Rightarrow Mammal(x))$.
• Merit: Absolute Inferential Adequacy. It allows the AI to use strict mathematical Resolution theorem proving to guarantee absolute truth.
• Demerit: It is incredibly rigid and catastrophically fails at handling probability or vague concepts ("most dogs are friendly").

A graphical architecture inspired by human psychological memory. Knowledge is violently represented as a massive directed graph.

• Mechanism: Nodes represent objects or concepts (e.g., Bird, Tweety). Directed edges represent strict relationships (e.g., IS-A, HAS-A).
• Example: Node(Tweety) $\stackrel{IS-A}{\to }$ Node(Bird) $\stackrel{HAS-A}{\to }$ Node(Wings).
• Merit: It handles Property Inheritance flawlessly. The AI mathematically traces the graph from Tweety up to Bird to instantly deduce that Tweety has wings, without explicitly storing that fact in Tweety's node. Highly efficient.

An architectural precursor to Object-Oriented Programming (OOP), proposed by Marvin Minsky.

• Mechanism: Knowledge is aggressively grouped into structured objects called "Frames". Each Frame has "Slots" (attributes) and "Facets" (values, default values, or executable procedures).
• Example: Frame: Classroom Slot Seats: Default 30 Slot Chalkboard: Yes Slot If_Added_Student: Execute Procedure Update_Roster().
• Merit: It flawlessly models stereotypical situations. If the AI walks into a room and identifies a chalkboard, the Classroom frame is violently instantiated, and the AI instantly makes massive default assumptions about the room without needing to scan every single object.

The architecture used in almost all early Expert Systems (like MYCIN).

• Mechanism: Strict IF-THEN conditional statements combined with a massive working memory database.
• Example: IF (Engine is overheated) AND (Coolant is empty) THEN (Status = Critical_Failure).
• Merit: Highly modular. You can violently inject a new rule into the database without rewriting the engine. It flawlessly supports Forward and Backward chaining algorithms.