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PMXStan: an R package to facilitate Bayesian PKPD modeling with Stan

From Yuan Xiong, David A James, Fei He, and Wenping Wang at Novartis. Full version of the poster here.

Cognitive skills rising and falling

David Hogg writes: I thought this was either interesting or bunk—using online games to infer how various kinds of cognitive intelligence vary with age. I thought it might be interesting to you on a number of levels. For one: Are there really categories of intelligence and can these map onto online games? For another: How […]

On deck this week

Mon: Cognitive skills rising and falling Tues: Anti-cheating robots Wed: Mindset interventions are a scalable treatment for academic underachievement — or not? Thurs: Most successful blog post ever Fri: Political advertising update Sat: Doomed to fail: A pre-registration site for parapsychology Sun: Mars Missions are a Scam Also, don’t forget what’s on deck for the […]

Flamebait: “Mathiness” in economics and political science

Political scientist Brian Silver points me to his post by economist Paul Romer, who writes: The style that I [Romer] am calling mathiness lets academic politics masquerade as science. Like mathematical theory, mathiness uses a mixture of words and symbols, but instead of making tight links, it leaves ample room for slippage between statements in […]

Comparing Waic (or loo, or any other predictive error measure)

Ed Green writes: I have fitted 5 models in Stan and computed WAIC and its standard error for each. The standard errors are all roughly the same (all between 209 and 213). If WAIC_1 is within one standard error (of WAIC_1) of WAIC_2, is it fair to say that WAIC is inconclusive? My reply: No, […]

Syllabus for my course on Communicating Data and Statistics

Actually the course is called Statistical Communication and Graphics, but I was griping about how few students were taking the class, and someone suggested the title Communicating Data and Statistics as being a bit more appealing. So I’ll go with that for now. I love love love this class and everything that’s come from it […]

Jason Chaffetz is the Garo Yepremian of the U.S. House of Representatives, and I don’t mean that in a good way.

Mike Spagat and Paul Alper points us to this truly immoral bit of graphical manipulation, courtesy of U.S. Representative Jason Chaffetz. Here’s the evil graph: Here’s the correction: From the news article by Zachary Roth: As part of a contentious back-and-forth in which Chaffetz repeatedly cut off [Planned Parenthood president Cecile] Richards, the congressman displayed […]

Hot hand explanation again

I guess people really do read the Wall Street Journal . . . Edward Adelman sent me the above clipping and calculation and writes: What am I missing? I do not see the 60%. And Richard Rasiej sends me a longer note making the same point: So here I am, teaching another statistics class, this […]

An unconvincing analysis claiming to debunk the health benefits of moderate drinking

Daniel Lakeland writes: This study on alcohol consumption (by Craig Knott, Ngaire Coombs, Emmanuel Stamatakis, and Jane Biddulph) was written up in the BMJ editorials as “Alcohol’s Evaporating health benefits.” They conveniently show their data in a table, so that they can avoid graphing a “J” shape that they constantly allude to being wrong… But […]

How to use lasso etc. in political science?

Tom Swartz writes: I am a graduate student at Oxford with a background in economics and on the side am teaching myself more statistics and machine learning. I’ve been following your blog for some time and recently came across this post on lasso. In particular, the more I read about the machine learning community, the […]

Fitting models with discrete parameters in Stan

This book, “Bayesian Cognitive Modeling: A Practical Course,” by Michael Lee and E. J. Wagenmakers, has a bunch of examples of Stan models with discrete parameters—mixture models of various sorts—with Stan code written by Martin Smira! It’s a good complement to the Finite Mixtures chapter in the Stan manual.

On deck through the rest of 2015

There’s something for everyone! I had a lot of fun just copying the titles to make this list, as I’d already forgotten about a lot of this stuff. Here are the scheduled posts, in order through 31 Dec: Fitting models with discrete parameters in Stan How to use lasso etc. in political science? An unconvincing […]

The Final Bug, or, Please please please please please work this time!

I’ve been banging my head against this problem, on and off, for a couple months now. It’s an EP-like algorithm that a collaborator and I came up with for integrating external aggregate data into a Bayesian analysis. My colleague tried a simpler version on an example and it worked fine, then I’ve been playing around […]

Annals of Spam

OK, explain to me this email: God day, How are you? My name is **. I came across your contact email at the University of Cyprus, Department of Economics. I seek for a private Economics teacher for my Daughter. I would like to know if you would be available for job. If you would be […]

Low-power pose

“The samples were collected in privacy, using passive drool procedures, and frozen immediately.” Anna Dreber sends along a paper, “Assessing the Robustness of Power Posing: No Effect on Hormones and Risk Tolerance in a Large Sample of Men and Women,” which she published in Psychological Science with coauthors Eva Ranehill, Magnus Johannesson, Susanne Leiberg, Sunhae […]

Amtrak is evil

Hmmmm, coverage for travel delay, that might not be so bad. This is Amtrak, after all. Let’s click through to the fine print: They’ll cover me for a departure delay of six or more hours, huh? Nice try in your attempt to scam me out of $8.50. It didn’t work this time, but, hey, why […]

Draw your own graph!

Bob writes: You must have seen this. I like it. But not enough to spend time blogging about it. I’ll try blogging it myself . . . OK, yeah, this interactive graph is great. It reminds me of “scatterplot charades” exercises we do in class from time to time. Somebody should write a program so […]


I don’t know if he has to say that this body type are actually better for a baseball player. Maybe it’s enough to just make the case that, Moneyball-style, players with this shape are underrated. P.S. I still don’t see why James chose in his book to summarize players by games played, home runs, RBI, […]

What was the worst statistical communication experience you’ve ever had?

In one of the jitts for our statistical communication class we asked, “What was the worst statistical communication experience you’ve ever had?” And here were the responses (which I’m sharing with permission from the students): Not sure if this counts, but I used to work with a public health researcher who published a journal article […]

“I do not agree with the view that being convinced an effect is real relieves a researcher from statistically testing it.”

Florian Wickelmaier writes: I’m writing to tell you about my experiences with another instance of “the difference between significant and not significant.” In a lab course, I came across a paper by Costa et al. [Cognition 130 (2) (2014) 236-254 ( In several experiments, they compare the effects in two two-by-two tables by comparing the […]