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Does your time as a parent make a difference?

A colleague writes: Thought you might be interested in this front page data journalism take down of an article. I don’t know the article but this amounts to a journalist talking with someone who didn’t like the piece and ripping it based on a measurement detail. Show More Summary

Random Total

Our task today is to generate a set of k random positive integers that add up to a given totaln. For instance, if we want 4 random numbers that add up to 9, there are six possible results (not counting permutations of them): {6,1,1,1}, {5,2,1,1}, {4,3,1,1}, {4,2,2,1}, {3,3,2,1} and {3,2,2,2}. An easy way to do […]

Applied regression and multilevel modeling books using Stan

Edo Navot writes: Are there any plans in the works to update your book with Prof. Hill on hierarchical models to a new edition with example code in Stan? Yes, we are planning to break it up into 2 books and do all the modeling for both books in Stan. Show More Summary

“Best Linear Unbiased Prediction” is exactly like the Holy Roman Empire

Dan Gianola pointed me to this article, “One Hundred Years of Statistical Developments in Animal Breeding,” coauthored with Guilherme Rosa, which begins: Statistical methodology has played a key role in scientific animal breeding. Approximately one hundred years of statistical developments in animal breeding are reviewed. Show More Summary

Postdoc in psychometrics in Cardiff

Richard Morey writes: I have a PhD position available at Cardiff University that I was hoping you might be able to publicise on your blog. It is for UK/EU students, and the project is negotiable but should be methods or statistical cognition. Show More Summary

Semigroup Puzzles

Two puzzles that involve nothing but playing with equations.

The posterior distribution of the likelihood ratio as a summary of evidence

Gabriel Marinello writes: I am a PhD student in Astrophysics and am writing this email to you because an enquiry about point null hypothesis testing (H0: Theta = Theta0 and H1: Theta != Theta0) in a bayesian context and I think that your pragmatic stance would be helpful. Show More Summary

Leonardo Numbers

The Leonardo numbers A001595 are defined as L0 = 1, L1 = 1, Ln = Ln?2 + Ln?1 + 1; Dijkstra discusses Leonardo numbers in EWD797, and uses them in the analysis of smoothsort. Leonardo numbers are similar to Fibonacci numbers, and are related by the formula Ln = 2 Fn+1 ? 1. Your task […]

Behind The Numbers: American Pharoah and 37 Years

By winning horse racing's Triple Crown this past weekend, American Pharoah entered the conversation on where he stands among all-time great thoroughbreds. But ranking American Pharoah is a subjective game.

“The psychologists are getting a hard time for doing what they do, whereas people doing real harm to society are happily roaming around like free range chicken”

Shravan Vasishth writes: At least people like Amy Cuddy are just doing bullshit research that’s harmless (after all, raising your arms up high before an interview is unlikely to hurt society much). But check out this MIT “Professor”Show More Summary

On deck this week

Mon: “The psychologists are getting a hard time for doing what they do, whereas people doing real harm to society are happily roaming around like free range chicken” Tues: The posterior distribution of the likelihood ratio as a summary...Show More Summary

What to do to train to apply statistical models to political science and public policy issues

Taylor Good writes: I am a graduate of a state school with a BS in Math and a BA in Political Science, and I was wondering if you could give me some career advice. Knowing how you got to where you are now, what path would you adviseShow More Summary

“History is the prediction of the present”

Ethan Bolker sent me an email with the above title and wrote: That’s the first sentence of a Louis Menand book review in the March 30 New Yorker. It touches on some ideas you play with. If you haven’t seen it, you might put it on your...Show More Summary

Better Bets on American Pharoah?

Wagering on American Pharoah to place (come in second or better) or show (third or better)--even for horse players who are convinced the highly touted winner of the Kentucky Derby and the Preakness Stakes is destined to cross the Belmont wire first--might be the best bets.

Should you get the blood transfusion?

Gur Huberman writes: Apropos Ethics & Logistic Regression, the piece you wrote with Madigan: In late 2001 I [Gur] broke my femur trying to rollerblade with my daughter. (No IQ award for that.) I had surgery and my recovery was slow. Every time I tried to get on crutches I’d collapse and faint. Show More Summary

Most Living People

We have today an exercise inspired by those “programming challenge” websites where you upload code and an automated judge tells if you pass or fail and how your time compares to other programmers. I haven’t seen this particular problem at one of those sites, but it feels like something they would do; this would also […]

A quick one

Fabio Rojas asks: Should I do Bonferroni adjustments? Pros? Cons? Do you have a blog post on this? Most social scientists don’t seem to be aware of this issue. My short answer is that if you’re fitting mutlilevel models, I don’t think...Show More Summary

We need a title for our Daily Beast column

Kaiser and I will soon start a weekly column for the Daily Beast, focusing on statistics that are cited in political and civic debates. The question is, what to call it? We have a few possibilities but aren’t thrilled with any of them. Show More Summary

Nested approximate subgroups

Suppose that are two subgroups of some ambient group, with the index of in being finite. Then is the union of left cosets of, thus for some set of cardinality. The elements of are not entirely arbitrary with regards to. For instance, if is a normal subgroup of, then for […]

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