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# All Blogs / Academics / Mathematics / Popular

### Just imagine if Ed Wegman got his hands on this program—it could do wonders for his research productivity!

Brendan Nyhan writes: I’d love to see you put some data in here that you know well and evaluate how the site handles it. The webpage in question says: Upload a data set, and the automatic statistician will attempt to describe the final column of your data in terms of the rest of the data. Show More Summary

### Discretised wave equations

The wave equation is usually expressed in the form where is a function of both time and space, with being the Laplacian operator. One can generalise this equation in a number of ways, for instance by replacing the spatial domain with some other manifold and replacing the Laplacian with the Laplace-Beltrami operator or adding […]

### Integral Octonions (Part 7)

Greg Egan just showed that $\mathrm{E}_{10}$: is the lattice of $2 \times 2$ self-adjoint matrices with integral octonions as entries! Here's the proof.

### “The Firth bias correction, penalization, and weakly informative priors: A case for log-F priors in logistic and related regressions”

Sander Greenland sent me this paper that he wrote with Mohammad Ali Mansournia, which discusses possible penalty functions for penalized maximum likelihood or, equivalently, possible prior distributions for Bayesian posterior mode estimation, in the context of logistic regression. Show More Summary

### A (not so well-known) theorem of Fouvry, and a challenge

A few weeks ago, as already mentioned, I was in Oxford for the LMS-CMI summer school on bounded gaps between primes. My mini-course on this occasion was devoted to the ideas and results underlying Zhang’s original approach, based on expanding the exponent of distribution of primes in arithmetic progressions to large moduli. In the first […]

### Social research is not the same as health research: Macartan Humphreys gives new guidelines for ethics in social science research

In reaction to the recent controversy about a research project that interfered with an election in Montana, political scientist Macartan Humphreys shares some excellent ideas on how to think about ethics in social science research: Social...Show More Summary

### Gaussian Integers, Part 1

Gaussian integers are complex numbers of the form a + b i where both a and b are integers. They obey the normal laws of algebra for addition, subtraction and multiplication. Division works, too, but is a little bit complicated: Addition: (a + b? i) + (x + y?i) = (a + x) + (b […]

### My talk today at the University of Michigan, 4pm at the Institute for Social Research

Generalizing from sample to population Andrew Gelman, Department of Statistics, Columbia University We’ve been hearing a lot about “data” recently, but data are generally a means to an end, with the goal being to learn about some population of interest. Show More Summary

### On deck this week

Mon: My talk today at the University of Michigan, 4pm at the Institute for Social Research Tues: Social research is not the same as health research: Macartan Humphreys gives new guidelines for ethics in social science research Wed: “The...Show More Summary

### On deck this month

My talk today at the University of Michigan, 4pm at the Institute for Social Research Social research is not the same as health research: Macartan Humphreys gives new guidelines for ethics in social science research “The Firth bias correction,...Show More Summary

### Ray Could Write

Now he is scattered among a hundred cities And wholly given over to unfamiliar affections, To find his happiness in another kind of wood And be punished under a foreign code of conscience.... You were silly like us; your gift survived...Show More Summary

### This is where they publish the stuff that can’t make it into Psychological Science

N=22 (link from here and here). I was unhappy to see that the two news articles took the study at face value. Photoplethysmograph, indeed. As Daniel Kahneman might say, “You have no choice but to accept that the major conclusions ofShow More Summary

### A Montana resident just sent me this

He got it in the mail and writes, “I don’t recall receiving the original mailer, but I probably would have just tossed it with the rest of the election mail I was getting.” P.S. Wouldn’t it be funny if this letter was actually sent from...Show More Summary

### Boo! Who’s afraid of availability bias?

Just in time for Halloween: I came across this 2-minute video by Brian Zikmund-Fisher, a professor of Health Behavior and Health Education at the University of Michigan, and I took a look because I was curious what he had to say. The...Show More Summary

### Daylight Saving Time Origins: From Ben Franklin to WWI Germany

Though he didn't call it daylight saving time, Benjamin Franklin was the first to conceive of the idea.

### Invasive Species, PTAs and Fantasy Football (Statshot)

The U.S. government is fighting several introduced animal species that are crowding out natives. The number of nonprofits supporting U.S. public schools grew sharply between 1995 and 2010. Last weekend, the Pittsburgh Steelers’ Ben Roethlisberger earned the fifth-highest fantasy point total by a quarterback in the past 10 years.

### Belphegor Primes

Belphegor is one of the Seven Princes of Hell, charged with helping people make ingenious inventions and discoveries. Simon Singh gave the name Belphegor’s Prime to the number 1000000000000066600000000000001, which is the Number of the Beast, 666, from the Apocalypse, surrounded on each side by an unlucky 13 zeroes. Generally, Belphegor numbers Bn = (10^(n+3) […]

### Was it really necessary to do a voting experiment on 300,000 people? Maybe 299,999 would’ve been enough? Or 299,998? Or maybe 2000?

There’s been some discussion recently about an experiment done in Montana, New Hampshire, and California, conducted by three young political science professors, in which letters were sent to 300,000 people, in order to (possibly) affect their voting behavior. Show More Summary

### Statistical distribution of incomes in different countries, and a great plot

This post is by Phil Price. This article in the New York Times is pretty good, and the graphics are excellent…especially the interactive graphic halfway down, entitled “American Incomes Are Losing Their Edge, Except at the Top” (try mousing over the gray lines and see what happens). Show More Summary

### I love it when I can respond to a question with a single link

Shira writes: This came up from trying to help a colleague of mine at Human Rights Watch. He has several completely observed variables X, and a variable with 29% missing, Y. He wants a histogram (and other descriptive statistics) of a “filled in” Y. Show More Summary