Artificial Intelligence

Foundations Of AI

History of AI

AI has gone through repeated cycles of hype and disappointment ("AI winters") — understanding this history explains why the field is organized the way it is tod

JrCodex·7 min read

Jr Codex AI Notes

Level: Beginner Prerequisites: Chapter 1 Time to complete: ~20 minutes


Table of Contents

  1. Why History Matters for Learning AI
  2. The Birth of AI (1940s-1956)
  3. The Golden Years (1956-1974)
  4. The First AI Winter (1974-1980)
  5. Expert Systems Boom & Bust (1980-1993)
  6. The Statistical/ML Turn (1990s-2010)
  7. The Deep Learning Era (2012-Present)
  8. Lessons from AI's Boom-Bust Cycles
  9. Summary & Next Steps

1. Why History Matters for Learning AI

AI has gone through repeated cycles of hype and disappointment ("AI winters") — understanding this history explains why the field is organized the way it is today, and why this curriculum covers both classical techniques (Modules 2-3, largely from the "Golden Years") and modern deep learning (a separate dedicated notes folder) rather than treating AI as a single, uniform subject.

The Full Timeline, At a Glance
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  1940s-56    Birth: early ideas, Turing's paper, the Dartmouth Workshop
  1956-74      Golden Years: huge optimism, early wins, big funding
  1974-80        First AI Winter: overpromising meets underdelivering
  1980-93          Expert Systems boom, then a second bust
  1990s-2010          The statistical/ML turn — quieter, steadier progress
  2012-now               Deep Learning era — massive capability jump
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2. The Birth of AI (1940s-1956)

Key Milestones
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  1943   McCulloch & Pitts propose a mathematical model of a
          neuron — the conceptual root of neural networks (DL notes)
  1950    Alan Turing publishes "Computing Machinery and
             Intelligence," proposing the Turing Test (Ch.1)
  1956      The Dartmouth Workshop — the term "Artificial
              Intelligence" is coined by John McCarthy; widely
              considered the FOUNDING event of AI as a field
─────────────────────────────────────────

The Dartmouth Workshop's proposal captured the field's founding optimism: organizers believed that "every aspect of learning...can in principle be so precisely described that a machine can be made to simulate it" — and that meaningful progress could be made by a small group over a single summer. This optimism (and its eventual collision with reality) is a pattern that recurs throughout AI's history.


3. The Golden Years (1956-1974)

Early successes generated enormous confidence — narrow demonstrations were mistaken for signs of imminent general intelligence.

Notable Achievements
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  1957   The General Problem Solver (GPS) — an early system
          using SEARCH (Module 2) to solve puzzles
  1958    John McCarthy invents LISP, AI's dominant
             programming language for decades
  1965      ELIZA — a simple pattern-matching chatbot that
                convinced some users it understood them
                (an early, informal precursor to the Turing
                Test debate from Chapter 1)
  1969       Shakey the robot — combined perception, planning,
                 and action in a physical robot
─────────────────────────────────────────

Funding poured in (particularly from DARPA in the US), and prominent researchers made bold, now-famous predictions — including claims that human-level AI was only a decade or two away. These predictions would prove badly premature, setting up the first winter.


4. The First AI Winter (1974-1980)

What Went Wrong
─────────────────────────────────────────
  - Computers of the era had FAR too little memory and
    processing power for the ambitions researchers had
  - Many early techniques didn't SCALE — they worked on toy
    problems but collapsed on realistic, larger ones
    (a recurring theme, revisited in Module 2's search chapters)
  - The 1973 Lighthill Report (UK) sharply criticized AI's
    lack of practical progress, leading to major funding cuts
  - DARPA also significantly cut AI funding in the US following
    similarly disappointing results
─────────────────────────────────────────

"AI Winter" became the term for this pattern: a period of reduced funding and interest following a period of unmet, overhyped expectations — this first winter would not be the last.


5. Expert Systems Boom & Bust (1980-1993)

The Second Wave
─────────────────────────────────────────
  1980s   EXPERT SYSTEMS (Module 3's rule-based AI) become
           commercially successful — systems like MYCIN
           (medical diagnosis) and XCON (configuring computer
           systems) demonstrate real business value
  1980s     Japan's "Fifth Generation Computer" project and
              similar government initiatives pour money back
              into AI research worldwide
  Late 1980s  Expert systems prove EXPENSIVE to build and
                maintain, brittle when facing situations outside
                their narrow, hand-coded rules — a second wave
                of disillusionment follows
  1987-93       The SECOND AI Winter — specialized "Lisp
                  Machine" hardware companies collapse, funding
                  contracts again
─────────────────────────────────────────

Expert systems (covered in Module 3, Chapter 6) demonstrated a recurring lesson: hand-coded knowledge works well within a narrow domain but doesn't generalize — a limitation that would later motivate the shift toward learning from data.


6. The Statistical/ML Turn (1990s-2010)

A Quieter, More Durable Era
─────────────────────────────────────────
  1990s   Researchers increasingly shift from hand-coded RULES
           toward STATISTICAL and PROBABILISTIC methods
           (Module 4's Bayesian networks trace to this era)
  1997     IBM's Deep Blue defeats world chess champion Garry
            Kasparov — a triumph of SEARCH (Module 2) and
            specialized hardware, not learning
  Early 2000s  Machine learning (a separate notes folder in
                  this curriculum) matures as its own
                  discipline — support vector machines, random
                  forests, and other now-classic ML algorithms
                  become standard tools
  2006          Geoffrey Hinton and colleagues popularize
                  techniques for training DEEP neural networks
                  effectively — planting the seed for the next era
─────────────────────────────────────────

This period avoided a third full "winter" — progress was steadier and less over-promised, partly because the field had learned from its earlier boom-bust cycles (Section 8).


7. The Deep Learning Era (2012-Present)

The Modern Explosion
─────────────────────────────────────────
  2012   AlexNet dramatically wins the ImageNet competition
          using deep convolutional neural networks — the
          moment widely credited with igniting the modern
          deep learning boom (full depth in the DL notes)
  2016    DeepMind's AlphaGo defeats a world champion Go player
            — combining deep learning WITH search (Module 2)
            and reinforcement learning (Module 5)
  2017      The "Transformer" architecture is introduced — the
              foundation of virtually every modern large language
              model (full depth in the NLP/LLM notes)
  2020-Present   GPT-3, GPT-4, Claude, and other large language
                    models demonstrate startlingly fluent,
                    general-purpose language capabilities
─────────────────────────────────────────

Why this era has (so far) avoided a third winter: unlike prior booms, deep learning's gains have been backed by dramatic, measurable improvements on real, hard benchmarks (image recognition, translation, game-playing, and more), combined with genuine commercial products reaching billions of users.


8. Lessons from AI's Boom-Bust Cycles

Recurring Patterns Worth Remembering
─────────────────────────────────────────
  1. Narrow success gets OVER-GENERALIZED into predictions of
     imminent general intelligence — this happened in the 1960s,
     the 1980s, and arguably continues to be debated today

  2. Techniques that work on TOY problems often fail to SCALE —
     a caution directly relevant to Module 2's search algorithms,
     which can explode in computational cost as problems grow

  3. Hand-coded knowledge (expert systems) is brittle outside
     its narrow domain — a key motivation for the entire field
     of machine learning that followed

  4. Genuine, durable progress tends to follow measurable,
     benchmarked improvements on real tasks — not just
     impressive demos or bold predictions
─────────────────────────────────────────

These lessons directly inform how this curriculum is structured — Module 2's search chapters, for instance, spend real time on why certain algorithms scale poorly, not just how they work in the abstract.


9. Summary & Next Steps

Key Takeaways

  • AI's history moves in cycles: the 1956 Dartmouth Workshop's optimism, the Golden Years' early wins, two separate "AI winters" driven by overpromising, and the current deep learning era beginning around 2012.
  • Expert systems (1980s) demonstrated that hand-coded knowledge works narrowly but doesn't generalize — a key motivation for the shift toward learning-based methods.
  • The current deep learning/LLM era has so far avoided a third winter by grounding progress in measurable benchmarks and real commercial products, not just bold predictions.
  • Recurring lesson across every cycle: narrow demonstrations get over-generalized into premature claims of general intelligence — a pattern worth watching for even today.

Concept Check

  1. What caused the first AI Winter (1974-1980), and what's the parallel to the second one in the late 1980s?
  2. Why did expert systems eventually fall out of favor despite early commercial success?
  3. What's different about the current deep learning era that has (so far) prevented a third AI winter?

Next Chapter

Chapter 3: Types of AI


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