Archive for population prediction

weapons of math destruction [book review]

Posted in Books, Kids, pictures, Statistics, University life with tags , , , , , , , , , , , , , , , on December 15, 2016 by xi'an

wmd As I had read many comments and reviews about this book, including one by Arthur Charpentier, on Freakonometrics, I eventually decided to buy it from my Amazon Associate savings (!). With a strong a priori bias, I am afraid, gathered from reading some excerpts, comments, and the overall advertising about it. And also because the book reminded me of another quantic swan. Not to mention the title. After reading it, I am afraid I cannot tell my ascertainment has changed much.

“Models are opinions embedded in mathematics.” (p.21)

The core message of this book is that the use of algorithms and AI methods to evaluate and rank people is unsatisfactory and unfair. From predicting recidivism to fire high school teachers, from rejecting loan applications to enticing the most challenged categories to enlist for for-profit colleges. Which is indeed unsatisfactory and unfair. Just like using the h index and citation ranking for promotion or hiring. (The book mentions the controversial hiring of many adjunct faculty by KAU to boost its ranking.) But this conclusion is not enough of an argument to write a whole book. Or even to blame mathematics for the unfairness: as far as I can tell, mathematics has nothing to do with unfairness. Some analysts crunch numbers, produce a score, and then managers make poor decisions. The use of mathematics throughout the book is thus completely inappropriate, when the author means statistics, machine learning, data mining, predictive algorithms, neural networks, &tc. (OK, there is a small section on Operations Research on p.127, but I figure deep learning can bypass the maths.) Continue reading

Bad graph of the day

Posted in Books, Statistics with tags , , , on October 30, 2009 by xi'an

Another meaningless graph found in the November issue of La Recherche: a histogram of the predictions of the World population by 2005 attached to a brief discussion of the challenges of providing food for this population. No mention is made of the source(s) for this absurd agglomerate of predictions, (could I add mine as well?!) while the discussion picks the median prediction for its reference number: as if Science was run by majority rule… As an unflattering coincidence (for La Recherche!), the other French monthly popular science magazine Pour la Science has simultaneously published a rather well-argumented special issue on randomness (by Jaroslaw Strzalko, Juliusz Grabski and Tomasz Kapitaniak who are Polish physicists), refering to one recent paper by Persi Diaconis on the randomness of coin tosses. Being associated with Scientific American certainly helps in producing quality papers! (There is also a paper by Ivar Ekeland in the same issue, as well as the paper by Andrew Gelman already signaled.)