# Events

Portland State University

Fariborz Maseeh Department of Mathematics & Statistics

The Maseeh Mathematics and Statistics Colloquium Series*

presents

Michael Perlman

~Department of Statistics,

University of Washington ~

Two Statistical Vignettes: Simpson's Paradox and Shaved Dice

Abstract:

1. Simpson's Paradox occurs for events A, B, and C if A and B are
positively correlated given B, positively correlated given not-B, but
are negatively correlated in the aggregate. If a 2x2x2 table is chosen
"at random", what is the probability that it will exhibit Simpson's
Paradox? 2. Persi Diaconis has fascinated audiences at all levels with
the following question: If one face of a standard gaming die is shaved
uniformly by a specified fraction $s$, express the new face
probabilities as a function of $s$. This apparently simple problem
appears to be intractable. However, this leads to an interesting
statistical question: if the shaved dice are thrown in pairs, as
typical in the game of craps, what is the most efficient design for
accurate estimation of the new face probabilities? (It will benefit the
audience to review the properties of the Fisher information number
beforehand.) (This is joint work with Marios Pavlides, with the
assistance of Fred Bookstein.)

Friday, April 23, 2010, 3:15pm

Smith Memorial Student Union room 328

(Refreshments served at 3:00 in same location)

* Sponsored by the Maseeh Mathematics and Statistics Colloquium Series
Fund and the Fariborz Maseeh Department of Mathematics &
Statistics, PSU. This event is free and open to the public.