1.1 Introduction to Artificial Intelligence

What is Artificial Intelligence?

Artificial Intelligence (AI) is the science and engineering of making intelligent machines — particularly intelligent computer programs. It is related to the similar task of using computers to understand human intelligence, but AI does not have to confine itself to biologically observable methods.

Definitions of AI

AI has been defined in four ways based on two dimensions:

Human-likeRational
ThinkingSystems that think like humansSystems that think rationally
ActingSystems that act like humansSystems that act rationally

1. Acting Humanly (Turing Test Approach) A computer passes the Turing Test if a human interrogator cannot distinguish the machine from a human after questioning both. Required capabilities:

  • Natural language processing
  • Knowledge representation
  • Automated reasoning
  • Machine learning

2. Thinking Humanly (Cognitive Modeling) Understanding how humans think and modeling it in computers. Uses introspection, psychological experiments, and brain imaging.

3. Thinking Rationally (Laws of Thought) Using logic to reason correctly. Aristotle’s syllogisms were early examples:

  • All men are mortal
  • Socrates is a man
  • Therefore, Socrates is mortal

4. Acting Rationally (Rational Agent) A rational agent acts to achieve the best outcome or the best expected outcome given uncertainty. This is the dominant approach in modern AI.

Foundations of AI

AI draws from multiple disciplines:

1. Philosophy

  • Can formal rules describe rational thinking?
  • How does the mind arise from the brain?
  • Where does knowledge come from?

2. Mathematics

  • Formal representation and proof
  • Algorithms and complexity
  • Probability theory

3. Economics

  • Decision theory
  • Game theory
  • Utility functions

4. Neuroscience

  • How do biological brains process information?
  • Neural networks inspired by brain structure

5. Psychology

  • Cognitive psychology — how do humans think?
  • Behaviorism — stimulus-response learning

6. Computer Engineering

  • Hardware that enables AI systems
  • Processing power for training models

7. Control Theory

  • Systems that regulate themselves
  • Feedback mechanisms

8. Linguistics

  • Language structure and meaning
  • Natural language understanding

Subareas of AI

SubareaDescriptionExamples
Search & PlanningFinding solutions in state spacesChess, path planning
Knowledge RepresentationStoring and using knowledgeExpert systems
Natural Language ProcessingUnderstanding human languageChatGPT, translation
Computer VisionUnderstanding images and videoFace recognition
Machine LearningLearning from dataImage classification
RoboticsPhysical agents in the worldSelf-driving cars
Expert SystemsDomain-specific reasoningMedical diagnosis
Speech RecognitionConverting speech to textSiri, Alexa

History of AI — Key Milestones

YearMilestone
1943McCulloch & Pitts — first mathematical model of neuron
1950Alan Turing proposes the Turing Test
1956Dartmouth Conference — AI coined as a field
1966ELIZA — first chatbot
1972PROLOG — logic programming language
1980sExpert systems boom
1997Deep Blue beats chess world champion
2012Deep learning revolution (AlexNet)
2016AlphaGo beats Go world champion
2022ChatGPT — large language models

AI vs Human Intelligence

AspectHuman IntelligenceArtificial Intelligence
LearningExperience-basedData-driven
SpeedSlowVery fast
MemoryLimited, fadesUnlimited, perfect
CreativityHighImproving
Common senseNaturalStill limited
AdaptabilityHighTask-specific

Practice Questions

Short Answer (2 marks each)

  1. Define Artificial Intelligence. What are the four ways AI has been defined?
  2. What is the Turing Test? What capabilities does it require?
  3. List any four subareas of AI with examples.
  4. What is a rational agent?

Long Answer (8 marks each)

  1. Explain the foundations of AI in detail with contributions from each discipline.
  2. Compare and contrast the four definitions of AI with suitable examples.
  3. Trace the history of AI from 1943 to the present. What were the major milestones?

Think & Apply

  1. Is a calculator an AI system? Justify your answer.
  2. Give three examples of AI applications you use in daily life. Which subarea of AI does each belong to?
  3. What are the limitations of the Turing Test?

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