Monday, October 26th, 2009
The Communicative Lexicon Hypothesis – Piantadosi, Tily & Gibson (2009)
Presents two experiments to support the Communicative Lexicon Hypothesis which states that human lexical systems are efficient solutions to the problem of communication for the human language processor. Shows that information or predictability in context based on trigrams is a better predictor of word length than raw collection frequency. Informativity discriminates between all word lengths while frequency just distinguishes between one syllable words and all the rest. The second experiment tries to show that lexical stress is placed on more informative syllables across a number of languages. Shows a significant difference between the residual entropy in stressed syllables and unstressed syllables. The measure of residual entropy is problematic because it does not take into account the position of the syllable in the word, the influence of other syllables on the given syllables entropy, or the informatively of the words in context.
Friday, October 23rd, 2009
Language Evolution and Information Theory – Plotkin & Nowak (2000)
Links Evolutionary Game Theory to Shannon’s Information Theory. Shows that with a noisy channel their is a limit to how much adding signals can improve fitness. The limit can be achieved by using combinations of signals to form words so that now a group of signals designate a state rather than individual signals. This allows the communication channel to reduce error exponentially in the number of signals and surpass the fitness limit of a non combinatorial signal system. Provides a framework for modeling different levels of linguistic structure in a probabilistic manner and to examine the dynamics of such systems.
Sunday, October 18th, 2009
The Myth of the Rational Market: A History of Risk, Reward, and Delusion on Wall Street
By Justin Fox 2009
400 pages
A history of the Rational Market hypothesis. Chronicles the first rigorous use of mathematics and game theory to study economic behavior, the people who did it and its effects on financial markets. Documents the movement of ideas about the rational market from economics to finance and finally to large trading operations. Shows how academic theories leave the tower through the work of many prominent economists and what they leave behind in the process. Take away message: A theory is only as good as its assumptions. People are creatures of habit with little historical perspective.