CSCE 420 Lecture 2

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Intelligence

What is Artificial Intelligence?

We ask ourselves a more fundamental question: What is intelligence?

  • Inter... (Interpretation?)
  • Learning/Adapting
  • Problem-solving
  • Goal-oriented behavior
  • Responding: perception of environment
  • complexity/difficulty [1] — expertise

We have tests to measure intelligence: IQ, SAT, GRE

  • sometimes we do poorly on a test, but it does not describe our true ability/potential
  • Intelligence is multidimensional

Are humans the only measure of intelligence?

  • dolphins Face-grin.svg
  • non-human primates (great apes)
  • use of language (even fuzzy among humans, plausible in dolphins, but probably not among other animals)

(Leave it open-ended)


Thinking like a human Thinking ideally
psychology
behaviorism = stimulus/response
cognitive = mental models of representing concepts, imagery,and productive systems
philosophy
Sometimes humans don't think ideally…
Acting like a human Acting ideally
operational[2]
implementation doesn't matter
Turing test: evaluate whether computer is intelligent (indistinguishable from human behavior) by interacting with it (winner gets the Loebner prize
rationality: doing the right thing
optimization (heuristic/approx. solutions to NP-Hard problems)
control theory
objective performance

Philosophy

  • Aristotle: syllogism (ABBC. ∴ AC; e.g. Socrates is a man, all men are mortal, therefore socrates is mortal)
  • Renaissance: formal logic and mathematics (Boole, Frege, Tarski, Leibnitz, Wittgenstein); incompleteness (Gödel's theorems)
    • Can intelligence/knowledge be represented as logic?
    • Can intelligence be represented as a computable function? f(state, goal) -> action
    • Does an intelligent system require embodiment/grounding? (any intelligent being/system has to be connected to the real world: sensors)

Psychology

Strengths

  • Interpretation: we are good at visual/auditory perception and parsing natural language
  • Disambiguation: we automatically choose the most likely interpretation
  • Expertise and Judgement
  • Creativity
  • Analogy: we can solve a brand new problem by relating it to a previously solved problem
  • Adaptiveness
  • Rationality

Weaknesses

  • Irrational: influenced by emotions, morals, ethics (in good ways)
  • Biased
  • Calculating (with the exception of Arthur Benjamin)
  • Memory limitations [3]


Architectures

  1. Symbolic Systems Hypothesis (Simon, Newell; CMU; 1960)
    • Using associations/pointers/links/references to represent concepts
    • Manipulation of symbols in algebra (CAS), etc.
  2. Knowledge-based Systems (grew into Expert systems)
  3. Connectionism: neural networks, distributed encoding (abstract representation of neurons as nodes; each neuron has certain threshholds)
  4. Uncertainty, Bayesian probability

Footnotes

  1. acting in non-deterministic ways; e.g. we can solve NP-Complete problems with relative ease
  2. all that matters is whether the system produces the right behavior
  3. Long term memory might use associations (links) with other knowledge; takes more effort to recall from long-term