[gov3009-l] Randomness and Coincidences: Reconciling Intuition and Probability Theory

Anders Schwartz Corr corr@fas.harvard.edu
Sun, 20 Oct 2002 16:02:09 -0400 (EDT)

Randomness and Coincidences: Reconciling Intuition and Probability

Presentation by Tom Griffiths (Stanford University, Psychology
Coauthored by Joshua Tennenbaum (Stanford University, Psychology

Wednesday October 23 at noon
Center for Basic Research in the Social Sciences
34 Kirkland Street, Room 22
Lunch will be served.


People are notoriously bad at reasoning about chance. Our intuitions about
randomness and coincidences seem to be inconsistent with the normative
structure of statistics: events that are equally likely to arise by chance
differ in their subjective randomness, and we consistently underestimate
the probability of coincidences. I will argue that we can understand why
these apparent errors arise by focusing on the evidence observations
provide about the processes that generated them rather than their
probability of occurring by chance. As part of this argument, I will
present a simple Bayesian framework that gives predictions about both the
extent to which a set of events will seem random, and the strength of
coincidences. This framework accurately predicts behavior in a variety of
contexts, suggesting that statistics might yet contribute to understanding
our intuitions about chance.

The Research Workshop in Applied Statistics is a forum for graduate
students, faculty, and visiting scholars to present and discuss
statistical innovations and applications in the social sciences. For more
information, contact corr@fas.harvard.edu.

The paper may be accessed at:

The presenter's email is: