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Performing design calculations (type M and type S errors) on a routine basis?

Somebody writes writes: I am conducting a survival analysis (median follow up ~10 years) of subjects who enrolled on a prospective, non-randomized clinical trial for newly diagnosed multiple myeloma. The data were originally collected...Show More Summary

Spark for Linear Algebra: don’t

Here are some pretty pictures of empirical orthogonal functions (principal components in climatology jargon) calculated for the 3D field of ocean temperatures using data collected over 32 years, generated by computing a rank 20 PCA of a 2 Tb matrix. I’ve been doing a lot of programming recently, implementing truncated SVDs in Spark on large […]

New paper on psychology replication

The Open Science Collaboration, a team led by psychology researcher Brian Nosek, organized the replication of 100 published psychology experiments. They report: A large portion of replications produced weaker evidence for the original...Show More Summary

Maximum Product Of Two Primes Less Than N

Today we have a fun little exercise based on prime numbers. Given an integer n > 4, find the maximum product of two prime numbers such that the product is less than n. For instance, when n = 27, the maximum is 2 13 = 26, and when n = 50, the maximum is […]

A political sociological course on statistics for high school students

Ben Frisch writes: I am designing a semester long non-AP Statistics course for high school juniors and seniors. I am wondering if you had some advice for the design of my class. My currentthinking for the design of the class includes: 0) Brief introduction to R/ R Studio and descriptive statistics and data sheet structure. Show More Summary

Heath-Brown’s theorem on prime twins and Siegel zeroes

The twin prime conjecture is one of the oldest unsolved problems in analytic number theory. There are several reasons why this conjecture remains out of reach of current techniques, but the most important obstacle is the parity problem which prevents purely sieve-theoretic methods (or many other popular methods in analytic number theory, such as the […]

Vizzy vizzy vizzy viz

Nadia Hassan points me to this post by Matthew Yglesias, who writes: Here’s a very cool data visualization from that took me a minute to figure out because it’s a little bit unorthodox. The way it works is that it visualizes the entire world’s economic output as a circle. Show More Summary

Stan’s 3rd birthday!

Stan v1.0.0 was released on August 30, 2012. We’ve come a long way since. If you’re around and want to celebrate with some Stan developers and users, feel free to join us: Monday, August 31. 6 – 9 pm Untamed Sandwiches 43 W 39th St New...Show More Summary

“Can you change your Bayesian prior?”

Deborah Mayo writes: I’m very curious as to how you would answer this for subjective Bayesians, at least. I found this section of my book showed various positions, not in agreement. I responded on her blog: As we discuss in BDA and elsewhere,...Show More Summary

Collect Sets Of Ranges

A frequent idiom in data processing is the control-break idiom, where some processing must be done every time there is a change in some value. A simple example comes from collecting ranges, for instance, converting the sequence 0, 1, 2, 7, 21, 22, 108, 109 to the ranges 0-2, 7, 21-22, 108-109, where a break […]

“The belief was so strong that it trumped the evidence before them.”

I was reading Palko on the 5 cent cup of coffee and spotted this: We’ve previously talked about bloggers trying to live on a food stamp budget for a week (yeah, that’s a thing). One of the many odd recurring elements of these post is...Show More Summary

On deck this week

Mon: “The belief was so strong that it trumped the evidence before them.” Tues: “Can you change your Bayesian prior?” Wed: How to analyze hierarchical survey data with post-stratification? Thurs: A political sociological course on statistics...Show More Summary

We provide a service

A friend writes: I got the attached solicitation [see below], and Google found me your blog post on the topic. Thank you for quickly explaining what’s going on here! As far as I can see, they’ve removed the mention of payment from this...Show More Summary

Plaig! (non-Wegman edition)

Mark Vallen writes (link from here): What initially disturbed me about the art of Shepard Fairey is that it displays none of the line, modeling and other idiosyncrasies that reveal an artist’s unique personal style. His imagery appears...Show More Summary

That was easy

This came in the email from Tom Kertscher: Are you available this afternoon or Wednesday to talk about a fact-check article I’m doing on Gov. Scott Walker’s statement that Wisconsin is a “blue” state? I’m aware, of course, that Wisconsin has voted for the Democratic presidential nominee in each election since 1988. Show More Summary

Aahhhhh, young people!

Amusingly statistically illiterate headline from Slate: “Apple Notices That Basically Half the Population Menstruates.” Ummmm, let’s do a quick calculation: 50 – 12 = 38. If you assume the average woman lives to be 80, then the proportion of the population who is menstruating is approximately.5238/80 =.247. Show More Summary

Two Homework Problems

I can see from my statistics that the new academic year is beginning. Again, as in a previous exercise, in the spirit of helping programming students who are just starting a new school year, we have two typical homework problems: 1. Given an array of positive integers, find the inflection point where the total of […]

Data-analysis assignments for BDA class?

In my Bayesian data analysis class this fall, I’m planning on doing some lecturing and class discussion, but the core of the course will be weekly data-analysis assignments where they do applied statistics using Stan (to fit models) and R (to pre-process the data and post-process the inferences). Show More Summary

Announcing ALGECOM Fall 2016

The University of Michigan at Ann Arbor is proud to be hosting ALGECOM, the twice annual midwestern conference on algebra, geometry and combinatorics on Saturday, October 24. We will feature four speakers, namely, Jonah Blasiak (Drexel...Show More Summary

Playing With Numbers: A Fantasy Football Tip

With the first batch of the National Football League's preseason games in the books, it's that time for every armchair general manager to begin assessing the draft, keepers and a strategy for the season. Thanks to a new tool, we can incorporate injury risk into our planning.

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