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Archive of posts filed under the Zombies category.

When are Bayesian model probabilities overconfident?

Oscar Oelrich, Shutong Ding, Måns Magnusson, Aki Vehtari, and Mattias Villani write: Bayesian model comparison is often based on the posterior distribution over the set of compared models. This distribution is often observed to concentrate on a single model even when other measures of model fit or forecasting ability indicate no strong preference. Furthermore, a […]

2 reasons why the CDC and WHO were getting things wrong: (1) It takes so much more evidence to correct a mistaken claim than to establish it in the first place; (2) The implicit goal of much of the public health apparatus is to serve the health care delivery system.

Peter Dorman points to an op-ed by Zeynep Tufekci and writes: This is a high profile piece in the NY Times on why the CDC and WHO have been so resistant to the evidence for aerosol transmission. What makes it relevant is the discussion of two interacting methodological tics, the minimization of Type I error […]

The Javert paradox rears its ugly head

The Javert paradox is, you will recall, the following: Suppose you find a problem with published work. If you just point it out once or twice, the authors of the work are likely to do nothing. But if you really pursue the problem, then you look like a Javert. I labeled the paradox a few […]

Doubting the IHME claims about excess deaths by country

The Institute for Health Metrics and Evaluation at the University of Washington (IHME) was recently claiming 900,000 excess deaths, but that doesn’t appear to be consistent with the above data. These graphs are from Ariel Karlinsky, who writes: The main point of the IHME report, that total COVID deaths, estimated by excess deaths, are much […]

Blast from the past

Paul Alper points us to this news article, The Secret Tricks Hidden Inside Restaurant Menus, which is full of fun bits: There is now an entire industry known as “menu engineering”, dedicated to designing menus that convey certain messages to customers, encouraging them to spend more and make them want to come back for a […]

Indeed, the standard way that statistical hypothesis testing is taught is a 2-way binary grid. Both these dichotomies are inappropriate.

I originally gave this post the title, “New England Journal of Medicine makes the classic error of labeling a non-significant difference as zero,” but was I was writing it I thought of a more general point. First I’ll give the story, then the general point. 1. Story Dale Lehman writes: Here are an article and […]

Responding to Richard Morey on p-values and inference

Jonathan Falk points to this post by Richard Morey, who writes: I [Morey] am convinced that most experienced scientists and statisticians have internalized statistical insights that frequentist statistics attempts to formalize: how you can be fooled by randomness; how what we see can be the result of biasing mechanisms; the importance of understanding sampling distributions. […]

Thoughts inspired by “the Gospel of Jesus’s Wife”

1. Harvard’s current position on the matter This is at Harvard University’s website: But, no, it’s not a “Coptic Papyrus Fragment.” That’s a lie. Or, I guess, several years ago we could call that statement a mistake, but given that it’s been known to be false for several years, I think it’s fair to call […]

“The Multiverse of Methods: Extending the Multiverse Analysis to Address Data-Collection Decisions”

Jenna Harder writes: When analyzing data, researchers may have multiple reasonable options for the many decisions they must make about the data—for example, how to code a variable or which participants to exclude. Therefore, there exists a multiverse of possible data sets. A classic multiverse analysis involves performing a given analysis on every potential data […]

Is it really true that “the U.S. death rate in 2020 was the highest above normal since the early 1900s—even surpassing the calamity of the 1918 flu pandemic”?

tl;dr. No, it’s not true. The death rate increased by 15% from 2019 to 2020, but it jumped by 40% from 1917 to 1918. But, if so, why would anyone claim differently? Therein lies a tale. A commenter pointed to a news article with the above graphs and the following claim: The U.S. death rate […]

“Analysis challenges slew of studies claiming ocean acidification alters fish behavior”

Lizzie Wolkovich writes: Here’s an interesting new paper in climate change ecology that states, “Using data simulations, we additionally show that the large effect sizes and small within-group variances that have been reported in several previous studies are highly improbable.” I [Lizzie] wish I were more surprised, but mostly I was impressed they did the […]

More on that credulity thing

I see five problems here that together form a feedback loop with bad consequences. Here are the problems: 1. Irrelevant or misunderstood statistical or econometric theory; 2. Poorly-executed research; 3. Other people in the field being loath to criticize, taking published or even preprinted claims as correct until proved otherwise; 4. Journalists taking published or […]

When can we challenge authority with authority?

Michael Nelson writes: I want to thank you for posting your last decade of publications in a single space and organized by topic. But I also wanted to share a critique of your argument style as exemplified in your Annals of Surgery correspondence [here and here]. While I think it’s important and valuable that you […]

Why did it take so many decades for the behavioral sciences to develop a sense of crisis around methodology and replication?

“On or about December 1910 human character changed.” — Virginia Woolf (1924). Woolf’s quote about modernism in the arts rings true, in part because we continue to see relatively sudden changes in intellectual life, not merely from technology (email and texting replacing letters and phone calls, streaming replacing record sales, etc.) and power relations (for […]

Adjusting for differences between treatment and control groups: “statistical significance” and “multiple testing” have nothing to do with it

Jonathan Falk points us to this post by Scott Alexander entitled “Two Unexpected Multiple Hypothesis Testing Problems.” The important questions, though, have nothing to do with multiple hypothesis testing or with hypothesis testing at all. As is often the case, certain free-floating scientific ideas get in the way of thinking about the real problem. Alexander […]

The 2019 project: How false beliefs in statistical differences still live in social science and journalism today

It’s the usual story. PNAS, New York Times, researcher degrees of freedom, story time. Weakliem reports: [The NYT article] said that a 2016 survey found that “when asked to imagine how much pain white or black patients experienced in hypothetical situations, the medical students and residents insisted that black people felt less pain.” I [Weakliem] […]

Call for a moratorium on the use of the term “prisoner’s dilemma”

Palko writes: I’m not sure what the best way to get the ball rolling here would be (perhaps a kickstarter?) but we need to have a strictly enforced rule that no journalist or pundit is allowed to mention the prisoner’s dilemma for the next five or ten years, however long it takes to learn to […]

I have these great April Fools ideas but there’s no space for them in the margin of this blog

Not really. Actually I have no good April Fools ideas this year. Usually I write an April Fools post months in advance, but it’s been such an overwhelming year in so many ways with a pandemic, an attempted overthrow of the government, and lots more, that somehow the inspiration never came. Bu we should have […]

A tale of two epidemiologists: It was the worst of times.

A couple of commenters pointed me to the story of John Ioannidis and Gideon Meyerowitz-Katz. David Gorski tells the tale. Ioannidis still seems to be dealing with the after-effects of his extrapolation last year that there might be 10,000 coronavirus deaths in the United States. This was just a back-of-the-envelope calculation, and as Gorski says, […]

“Like a harbor clotted with sunken vessels”: update

A few years ago I reported on this story: In 2005, Michael Kosfeld, Markus Heinrichs, Paul Zak, Urs Fischbacher, and Ernst Fehr published a paper, “Oxytocin increases trust in humans.” According to Google, that paper has been cited 3389 times. In 2015, Gideon Nave, Colin Camerer, and Michael McCullough published a paper, “Does Oxytocin Increase […]

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