Skip to content
Archive of posts filed under the Decision Theory category.

Causal inference data challenge!

Susan Gruber, Geneviève Lefebvre, Tibor Schuster, and Alexandre Piché write: The ACIC 2019 Data Challenge is Live! Datasets are available for download (no registration required) at (bottom of the page). Check out the FAQ at The deadline for submitting results is April 15, 2019. The fourth Causal Inference Data Challenge is taking place […]

M. F. K. Fisher (1) vs. Serena Williams; Oscar Wilde advances

The best case yesterday was made by Manuel: Leave Joe Pesci at home alone. Wilde’s jokes may be very old, but he can use slides from The PowerPoint of Dorian Gray. As Martha put it, not great, but the best so far in this thread. On the other side, Jonathan wrote, “I’d definitely rather hear […]

Data partitioning as an essential element in evaluation of predictive properties of a statistical method

In a discussion of our stacking paper, the point came up that LOO (leave-one-out cross validation) requires a partitioning of data—you can only “leave one out” if you define what “one” is. It is sometimes said that LOO “relies on the data-exchangeability assumption,” but I don’t think that’s quite the right way to put it, […]

Oscar Wilde (1) vs. Joe Pesci; the Japanese dude who won the hot dog eating contest advances

Raghuveer gave a good argument yesterday: “The hot dog guy would eat all the pre-seminar cookies, so that’s a definite no.” But this was defeated by the best recommendation we’ve ever had in the history of the Greatest Seminar Speaker contest, from Jeff: Garbage In, Garbage Out: Mass Consumption and Its Aftermath Takeru Kobayashi Note: […]

Carol Burnett (4) vs. the Japanese dude who won the hot dog eating contest; Albert Brooks advances

Yesterday was a tough matchup, but ultimately John “von” Neumann was no match for a very witty Albert Einstein. The deciding argument, from Martha: I’d like to see Von Neumann given four parameters and making an elephant wiggle his trunk. And if he could do it, there would be the chance that Jim Thorpe could […]

John van Neumann (3) vs. Albert Brooks; Paul Erdos advances

We had some good arguments on both sides yesterday. For Erdos, from Diana Senechal: From an environmental perspective, Erdos is the better choice; his surname is an adjectival form of the Hungarian erdő, “forest,” whereas “Carson” clearly means “son of a car.” Granted, the son of a car, being rebellious and all, might prove especially […]

How post-hoc power calculation is like a shit sandwich

Damn. This story makes me so frustrated I can’t even laugh. I can only cry. Here’s the background. A few months ago, Aleksi Reito (who sent me the adorable picture above) pointed me to a short article by Yanik Bababekov, Sahael Stapleton, Jessica Mueller, Zhi Fong, and David Chang in Annals of Surgery, “A Proposal […]

Johnny Carson (2) vs. Paul Erdos; Babe Didrikson Zaharias advances

OK, our last matchup wasn’t close. Adam Schiff (unseeded in the “people whose name ends in f” category) had the misfortune to go against the juggernaut that was Babe Didrikson Zaharias (seeded #2 in the GOATs category). Committee chair or not, the poor guy never had a chance. As Diana Senechal wrote, “From an existential […]

New blog hosting!

Hi all. We’ve been having some problems with the blog caching, so that people were seeing day-old versions of the posts and comments. We moved to a new host and a new address,, and all should be better. Still a couple glitches, though. Right now it doesn’t seem to be possible to comment. We […]

Babe Didrikson Zaharias (2) vs. Adam Schiff; Sid Caesar advances

And our noontime competition continues . . . We had some good arguments on both sides yesterday. Jonathan writes: In my experience, comedians are great when they’re on-stage and morose and unappealing off-stage. Sullivan, on the other hand, was morose and unappealing on-stage, and witty and charming off-stage, or so I’ve heard. This comes down, […]

Ed Sullivan (3) vs. Sid Caesar; DJ Jazzy Jeff advances

Yesterday’s battle (Philip Roth vs. DJ Jazzy Jeff) was pretty low-key. It seems that this blog isn’t packed with fans of ethnic literature or hip-hop. Nobody in comments even picked up on my use of the line, “Does anyone know these people? Do they exist or are they spooks?” Isaac gave a good argument in […]

Philip Roth (4) vs. DJ Jazzy Jeff; Jim Thorpe advances

For yesterday’s battle (Jim Thorpe vs. John Oliver), I’ll have to go with Thorpe. We got a couple arguments in Oliver’s favor—we’d get to hear him say “Whot?”, and he’s English—but for Thorpe we heard a lot more, including his uniqueness as greatest athlete of all time, and that we could save money on the […]

The seminar speaker contest begins: Jim Thorpe (1) vs. John Oliver

As promised, we’ll be having one contest a day for our Ultimate Seminar Speaker contest, first going through the first round of our bracket, then going through round 2, etc., through to the finals. Here’s the bracket: And now we begin! The first matchup is Jim Thorpe, seeded #1 in the GOATs category, vs. John […]

On deck for the first half of 2019

OK, this is what we’ve got for you: “The Book of Why” by Pearl and Mackenzie Reproducibility and Stan MRP (multilevel regression and poststratification; Mister P): Clearing up misunderstandings about Becker on Bohm on the important role of stories in science This is one offer I can refuse How post-hoc power calculation is like a […]

Announcing the ultimate seminar speaker contest: 2019 edition!

Paul Davidson made the bracket for us (thanks, Paul!): Here’s the full list: Wits: Oscar Wilde (seeded 1 in group) Dorothy Parker (2) David Sedaris (3) Voltaire (4) Veronica Geng Albert Brooks Mel Brooks Monty Python Creative eaters: M. F. K. Fisher (1) Julia Child (2) Anthony Bourdain (3) Alice Waters (4) A. J. Liebling […]

Back by popular demand . . . The Greatest Seminar Speaker contest!

Regular blog readers will remember our seminar speaker competition from a few years ago. Here was our bracket, back in 2015: And here were the 64 contestants: – Philosophers: Plato (seeded 1 in group) Alan Turing (seeded 2) Aristotle (3) Friedrich Nietzsche (4) Thomas Hobbes Jean-Jacques Rousseau Bertrand Russell Karl Popper – Religious Leaders: Mohandas […]

Using multilevel modeling to improve analysis of multiple comparisons

Justin Chumbley writes: I have mused on drafting a simple paper inspired by your paper “Why we (usually) don’t have to worry about multiple comparisons”. The initial idea is simply to revisit frequentist “weak FWER” or “omnibus tests” (which assume the null everywhere), connecting it to a Bayesian perspective. To do this, I focus on […]

A couple of thoughts regarding the hot hand fallacy fallacy

For many years we all believed the hot hand was a fallacy. It turns out we were all wrong. Fine. Such reversals happen. Anyway, now that we know the score, we can reflect on some of the cognitive biases that led us to stick with the “hot hand fallacy” story for so long. Jason Collins […]

Should we be concerned about MRP estimates being used in later analyses? Maybe. I recommend checking using fake-data simulation.

Someone sent in a question (see below). I asked if I could post the question and my reply on blog, and the person responded: Absolutely, but please withhold my name because this is becoming a touchy issue within my department. The boldface was in the original. I get this a lot. There seems to be […]

My talk tomorrow (Tues) noon at the Princeton University Psychology Department

Integrating collection, analysis, and interpretation of data in social and behavioral research Andrew Gelman, Department of Statistics and Department of Political Science, Columbia University The replication crisis has made us increasingly aware of the flaws of conventional statistical reasoning based on hypothesis testing. The problem is not just a technical issue with p-values, not can […]