Probably Approximately Correct: Nature's Algorithms for Learning and Prospering in a Complex World
Nature's Algorithms for Learning and Prospering in a Complex World
From a leading computer scientist, a unifying theory that will revolutionize our understanding of how life evolves and learns.How does life prosper in a complex and erratic world? While we know that nature follows patterns,such as the law of gravity,our everyday lives are beyond what known science can predict. We nevertheless muddle through even in the absence of theories of how to act. But how do we do it?In Probably Approximately Correct , computer scientist Leslie Valiant presents a masterful synthesis of learning and evolution to show how both individually and collectively we not only survive, but prosper in a world as complex as our own. The key is probably approximately correct" algorithms, a concept Valiant developed to explain how effective behaviour can be learned. The model shows that pragmatically coping with a problem can provide a satisfactory solution in the absence of any theory of the problem. After all, finding a mate does not require a theory of mating. Valiant's theory reveals the shared computational nature of evolution and learning, and sheds light on perennial questions such as nature versus nurture and the limits of artificial intelligence.Offering a powerful and elegant model that encompasses life's complexity, Probably Approximately Correct has profound implications for how we think about behaviour, cognition, biological evolution, and the possibilities and limits of human and machine intelligence.
Leslie Valiant is the T. Jefferson Coolidge Professor of Computer Science and Applied Mathematics at Harvard University. He is a Fellow of the Royal Society and a member of the National Academy of Sciences. He is a winner of the Nevanlinna Prize from the International Mathematical Union, and the Turing Award, known as the Nobel of computing.
"[A]n engaging meditation on complexity and on how living things often unwittingly use math to navigate it."--"Scientific American" "Computer scientist Leslie Valiant celebrates Alan Turing as the progenitor of a third scientific revolution, potentially as profound as Newton's and Einstein's in transforming our understanding of the world. Why not a 'fourth revolution'--why omit Darwin? Because, Valiant dares to say, Darwin's theory is radically incomplete, and until it is equipped to make quantitative, verifiable predictions, evolution by natural selection cannot account for the complexity of living things and is not 'more than a metaphor.' But Valiant offers no drop of succor to creationists. Rather, he seeks to arm neo-Darwinian theory against their onslaughts by elucidating the mechanistic, quantitative basis it must have in a world 'without a designer.' The algorithms of computational learning theory, he posits, will be key--in particular, a special kind he calls 'ecorithms, ' which incorporate information gathered from the environment to improve an organism's 'performance.' Turing's heirs have only just begun to plot its equation."--"The Scientist" "["Probably Approximately Correct"] really shines as an introduction to computer science theory to the general public, providing a compact and accessible description of basic, important results ... . This is a book that should be on every computer scientist's shelf so that when someone asks, 'Why is computer science theory important?' the three word response can be, 'Read this book.'"--"SIGACT News" "A scholar at the intersection of computing and evolutionary neuroscience, Valiant explores 'ecorithms' algorithms that learn by interacting with their environment, not from their designer--and so are fundamental to the process of evolution. His text is clear and approachable, with some work; the argument is sweeping."--"Harvard Magazine" "This remarkable book is carefully const