What is AI

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What is AI?
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Acting Humanly The Turing Test

• Alan Turing (1912-1954)
• Computing Machinery and Intelligence (1950)

Imitation Game
Human
Human Interrogator
AI System
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Acting Humanly The Turing Test

• Predicted that by 2000, a machine might have a
  30 chance of fooling a lay person for 5 minutes.
• Anticipated all major arguments against AI in
• following 50 years.
• Suggested major components of AI knowledge,
• reasoning, language, understanding, learning.

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Thinking Humanly Cognitive Modelling

• Not content to have a program correctly solving a
  problem.
• More concerned with comparing its reasoning
  steps to traces of human solving the same
  problem.
• Requires testable theories of the workings of the
  
• human mind cognitive science.

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Thinking Rationally Laws of Thought

• Aristotle was one of the first to attempt to
  codify right thinking, i.e., irrefutable
  reasoning processes.
• Formal logic provides a precise notation and
  rules for representing and reasoning with all
  kinds of things in the world.
• Obstacles
• - Informal knowledge representation.
• - Computational complexity and resources.

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Acting Rationally

• Acting so as to achieve ones goals, given ones
  beliefs.
• Does not necessarily involve thinking.
• Advantages
• - More general than the laws of thought
  approach.
• - More amenable to scientific development than
• human-based approaches.

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What is Knowledge Engineering?

• Stuart Russell
• "The process of building a knowledge base"

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What is Knowledge Engineering?

• John Sowa
• "The application of logic and ontology to the
  task of building computable models of some domain
  for some purpose"
• (ontology the study of existence)

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What is Knowledge Engineering?

• A knowledge engineer
• Investigates a particular domain
• Determines what concepts are important
• Creates a formal representation of the objects
  and relations

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What is Knowledge Engineering?

• Building a knowledge base
• Decide what to talk about
• Decide on a vocabulary of predicates, functions,
  and constants
• Encode general knowledge about the domain
• Encode a description of the specific problem
  instance
• Pose queries to the inference procedure and get
  answers

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Principles of Knowledge Representation

• Knowledge Representation is
• A surrogate
• A set of ontological commitments
• A fragmentary theory of intelligent reasoning
• A medium for efficient computation
• A medium of human expressions
• (Randall Davis, Howard Schrobe, Peter Szolovits)

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Homework

• Reading
• "What is a knowledge representation?"
• Davis, R. Schrobe, H. Szolovits, P.