Allen B. Downey

Allen B. Downey

Professor of Computer Science at Olin College

Boston, Massachusetts

Allen Downey is a Professor of Computer Science at Olin College of Engineering. He has taught at Wellesley College, Colby College and U.C. Berkeley. He has a Ph.D. in Computer Science from U.C. Berkeley and Master's and Bachelor's degrees from MIT.

Think Bayes Think Bayes
by Allen B. Downey
September 2013
Print: $29.99
Ebook: $23.99

Think Python Think Python
by Allen B. Downey
August 2012
Print: $39.99
Ebook: $31.99

Think Complexity Think Complexity
by Allen B. Downey
March 2012
Print: $29.99
Ebook: $23.99

Think Stats Think Stats
by Allen B. Downey
July 2011
Print: $29.99
Ebook: $23.99

Allen B. blogs at:

Think X, Y and Z: What's in the pipeline?

April 12 2014

Greetings from PyCon 2014 in Montreal!  I did a book signing yesterday at the O'Reilly Media booth.  I had the pleasure of working side by side with David Beazley, who was signing copies of The Python Cookbook, now updated for Python 3 and, I assume, including all of the perverse… read more

The Internet and religious affiliation

April 07 2014

A few weeks ago I published this paper on arXiv: "Religious affiliation, education and Internet use".  Regular readers of this blog will recognize this as the article I was writing about in July 2012, including this article.A few days ago, MIT Technology Review wrote about my paper: How the Internet Is… read more

Freshman hordes slightly more godless than ever

March 06 2014

This article is an update to my annual series on one of the most under-reported stories of the decade: the fraction of college freshmen who report no religious preference has tripled since 1985, from 8% to 24%, and the trend is accelerating.In last year's installment, I made the bold prediction… read more

Correlation is evidence of causation

February 21 2014

In class last week, I was talking about correlation and linear regression, and I made the outrageous claim that correlation is evidence of causation.  One of my esteemed colleagues, who is helping out with the class, was sitting in the back of the room, and immediately challenged my claim.  It… read more

Are your data normal? Hint: no.

February 04 2014

One of the frequently-asked questions over at the statistics subreddit ( is how to test whether a dataset is drawn from a particular distribution, most often the normal distribution.There are standard tests for this sort of thing, many with double-barreled names like Anderson-Darling, Kolmogorov-Smirnov, Shapiro-Wilk, Ryan-Joiner, etc.But these tests are… read more

Bayesian statistics in Montreal

February 01 2014

I am happy to announce that I will be offering my tutorial, "Bayesian Statistics Made Simple" at PyCon 2014 in Montreal.  The tutorial is based on material from Think Bayes.  It includes some of the examples and exercises in the book.  Participants will work on examples during the workshop, so… read more

Webcast: There's Only One Test
October 04, 2011
Can I use a t-test if my data are non-normal? What if the sample size is small? What's an exact test? And how many tests are there, anyway? People working with real data are often confused about hypothesis testing and paralyzed by the number of tests...

Webcast: Bayesian Statistics Made Simple
October 26, 2012
Join Allen Downey, author of Think Stats: Probability and Statistics for Programmers for an introduction to Bayesian statistics using Python. Bayesian statistical methods are becoming more common and more important, but there are not many resources...

"This book is a quick and easy introduction to programming and to Python. It is among the clearest introductions to both topics that I have seen in a long time."
--Andrew Binstock, Dr. Dobbs

"The author does an excellent job talking about the different systems and programs that are used in this career. This would also be a great textbook if your in school learning what your doing in the programming field."
--Stephaine Szostak, cybertron reviews

"I highly recommend this text for a first course in Computer Science at both secondary and university levels. It is as its title suggests an introduction to Python for Thinkers."
--Ira Laefsky,

"If Professor Downey ever opens an online class for "Think Complexity" either synchronized or on UDemy I would sign up in a heartbeat."
--Eric Chou,

"This short but extremely exciting book is simultaneously an invitation to actively participate in what Stephen Wolfram has called "A New Kind of Science", and an introduction to "Data Structures" (what traditionally has been the second course in Computer Science) with an exciting new motivation."
--Ira Laefsky

"Think Complexity is not just another how-to-program-in-Python book."
--Si Dunn, Sagecreek Productions