Prof. Brain Blais has implemented the BEST model of two groups in emcee, a Python system for MCMC sampling. See his post about it here.

I’ve said it before and I’ll say it again: interaction is one of the key underrated topics in statistics. I thought about this today (OK, a couple months ago, what with our delay) when reading a post by Dan Kopf on the exaggeration of small truths. Or, to put it another way, statistically significant but […] The post Statistical significance, practical significance, and interactions appeared first on Statistical Modeling, Causal…

Kate Lee pointed me to a rather surprising inefficiency in matlab, exploited in Sylvia Früwirth-Schnatter’s bayesf package: running a gamma simulation by rgamma(n,a,b) takes longer and sometimes much longer than rgamma(n,a,1)/b, the latter taking advantage of the scale nature of b. I wanted to check on my own whether or not R faced the same […]

For those who have found it tough to keep up with Andrew Gelman's prolificacy, here are some brief summaries of several recent posts: On people obsessed with proving the statistical significance of tiny effects: "they are trying to use a bathroom scale to weigh a feather—and the feather is resting loosely in the pouch of a kangaroo that is vigorously jumping up and down." (link) [I left a comment. In…

Jose Duarte, Jarret Crawford, Charlotta Stern, Jonathan Haidt, Lee Jussim, and Philip Tetlock wrote an article, “Political Diversity Will Improve Social Psychological Science,” in which the argued that the field of social psychology would benefit from the inclusion of more non-liberal voices (here I’m using “liberal” in the sense of current U.S. politics). Duarte et […] The post Political Attitudes in Social Environments appeared first on Statistical Modeling, Causal Inference,…

I’m speaking in the “Yahoo Labs Big Thinkers” series on Friday 26 June. I hope I can live up to the title! My talk is on “Exploring the boundaries of predictability: what can we forecast, and when should we give up?” Essentially I will start with some of the ideas in this post, and then discuss the […]

Should Columbia University fire this guy just cos he says things like this: “You may think magic is make believe but this little bean has scientists saying they’ve found the magic weight loss cure for every body type—it’s green coffee extract.” “I’ve got the No. 1 miracle in a bottle to burn your fat. It’s […] The post A message from the vice chairman of surgery at Columbia University: “Garcinia…

Lena Groeger (of ProPublica) has written a beautiful piece about the Power of Wee Things. She talks about using small things, multiples, and units to display data and get people interested. The article goes through many, many examples covering many different areas and ideas. She also gave a great talk on the topic at OpenVis 2014. On a somewhat related … Continue reading Link: The Power of Wee Things

Pejman Mohammadi writes: I’m concerned with a problem in multiple hypothesis correction and, despite having read your article [with Jennifer and Masanao] on not being concerned about it, I was hoping I could seek your advice. Specifically, I’m interested in multiple hypothesis testing problem in cases when the test is done with a discrete finite […] The post Instead of worrying about multiple hypothesis correction, just fit a hierarchical model.…

A customer asked: How do we go about summing a finite series in SAS? For example, I want to compute for various integers n ≥ 3. I want to output two columns, one for the natural numbers and one for the summation of the series. Summations arise often in statistical […] The post Sum a series in SAS appeared first on The DO Loop.

One of my PhD students, Thilaksha Tharanganie, has been very successful in getting travel funding to attend conferences. She was the subject of a write-up in today’s Monash News. We encourage students to attend conferences, and provide funding for them to attend one international conference and one local conference during their PhD candidature. Thilaksha was […]

Note on an Article by Sir Ronald Fisher By Jerzy Neyman (1956) Summary (1) FISHER’S allegation that, contrary to some passages in the introduction and on the cover of the book by Wald, this book does not really deal with experimental design is unfounded. In actual fact, the book is permeated with problems of experimentation. […]

Here’s something I wrote in the context of one of those “power = .06″ studies: My criticism of the ovulation-and-voting study is ultimately quantitative. Their effect size is tiny and their measurement error is huge. My best analogy is that they are trying to use a bathroom scale to weigh a feather—and the feather is […] The post The feather, the bathroom scale, and the kangaroo appeared first on Statistical…

This is a supplement to the previous post about a new research paper on the effect of Alcoholics Anonymous, and an NY Times exposition that I commented on. A misreading of that article led me to complain about per-protocol analysis, which wasn't the methodology behind the Humphrey et. al. research. I will explain their methodology in this post (known as instrumental variables analysis). *** In the last post, I showed…

I, with my coathors, have submitted a new draft of our paper "The fallacy of placing confidence in confidence intervals". This paper is substantially modified from its previous incarnation. Here is the main argument:"[C]onfidence intervals may not be u...