Anti-Abortion Democrats, Jimmy Carter Republicans, and the Missing Leap Day Babies: Living with Uncertainty but Still Learning To learn about the human world, we should accept uncertainty and embrace variation. We illustrate this concept with various examples from our recent research (the above examples are with Yair Ghitza and Aki Vehtari) and discuss more generally […]

**Bayesian Statistics**category.

## Likelihood from quantiles?

Michael McLaughlin writes: Many observers, esp. engineers, have a tendency to record their observations as {quantile, CDF} pairs, e.g., x CDF(x) 3.2 0.26 4.7 0.39 etc. I suspect that their intent is to do some kind of “least-squares” analysis by computing theoretical CDFs from a model, e.g. Gamma(a, b), then regressing the observed CDFs against […]

## Questions about “Too Good to Be True”

Greg Won writes: I manage a team tasked with, among other things, analyzing data on Air Traffic operations to identify factors that may be associated with elevated risk. I think its fair to characterize our work as “data mining” (e.g., using rule induction, Bayesian, and statistical methods). One of my colleagues sent me a link […]

## Avoiding model selection in Bayesian social research

One of my favorites, from 1995. Don Rubin and I argue with Adrian Raftery. Here’s how we begin: Raftery’s paper addresses two important problems in the statistical analysis of social science data: (1) choosing an appropriate model when so much data are available that standard P-values reject all parsimonious models; and (2) making estimates and […]

## Dave Blei course on Foundations of Graphical Models

Dave Blei writes: This course is cross listed in Computer Science and Statistics at Columbia University. It is a PhD level course about applied probabilistic modeling. Loosely, it will be similar to this course. Students should have some background in probability, college-level mathematics (calculus, linear algebra), and be comfortable with computer programming. The course is […]

## Discussion of “Maximum entropy and the nearly black object”

From 1992. It’s a discussion of a paper by Donoho, Johnstone, Hoch, and Stern. As I summarize: Under the “nearly black” model, the normal prior is terrible, the entropy prior is better and the exponential prior is slightly better still. (An even better prior distribution for the nearly black model would combine the threshold and […]

## “A hard case for Mister P”

Kevin Van Horn sent me an email with the above title (ok, he wrote MRP, but it’s the same idea) and the following content: I’m working on a problem that at first seemed like a clear case where multilevel modeling would be useful. As I’ve dug into it I’ve found that it doesn’t quite fit […]

## My courses this fall at Columbia

Stat 6103, Bayesian Data Analysis, TuTh 1-2:30 in room 428 Pupin Hall: We’ll be going through the book, section by section. Follow the link to see slides and lecture notes from when I taught this course a couple years ago. This course has a serious workload: each week we have three homework problems, one theoretical, […]

## Discussion with Sander Greenland on posterior predictive checks

Sander Greenland is a leading epidemiologist and educator who’s strongly influenced my thinking on hierarchical models by pointing out that often the data do not supply much information for estimating the group-level variance, a problem that can be particularly severe when the number of groups is low. (And, in some sense, the number of groups […]

## Estimated effect of early childhood intervention downgraded from 42% to 25%

Last year I came across an article, “Labor Market Returns to Early Childhood Stimulation: a 20-year Followup to an Experimental Intervention in Jamaica,” by Paul Gertler, James Heckman, Rodrigo Pinto, Arianna Zanolini, Christel Vermeerch, Susan Walker, Susan M. Chang, and Sally Grantham-McGregor, that claimed that early childhood stimulation raised adult earnings by 42%. At the […]