## Columbo does posterior predictive checks

October 4, 2012
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I’m already on record as saying that Ronald Reagan was a statistician so I think this is ok too . . . Here’s what Columbo does. He hears the killer’s story and he takes it very seriously (it’s murder, and Columbo never jokes about murder), examines all its implications, and finds where it doesn’t fit [...]

## The New Zealand sun alibi

October 4, 2012
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BBC News, reporting on the results of a study of Vitamin D supplements, inserted a curious sentence: "The study, carried out in New Zealand, which gets more sunshine annually than the UK, found the vitamin D supplements increased blood levels of the vitamin. But this had no significant impact on the rate or severity of colds." (my italics) This is yet another study that shows supplements/drugs that succeed in making…

## Dice probabilities and the game of "craps"

October 4, 2012
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Gambling games that use dice, such as the game of "craps," are often used to demonstrate the laws of probability. For two dice, the possible rolls and probability of each roll are usually represented by a matrix. Consequently, the SAS/IML language makes it easy to compute the probabilities of various [...]

## Graphing Non-Proportional Hazards in R

October 4, 2012
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Update 30 July 2013: I've moved all of the functionality described in this post into an R package called simPH. Have a look. It is much easier to use. Update 30 December 2012: I updated the code HERE so that it keeps only the middle 95 percent of the...

## Comparing Energy Efficiency in the San Gabriel Valley

October 3, 2012
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Comparing Energy Efficiency in the San Gabriel Valley [pmcworld.com] by San Francisco-based Stamen Design, reveals how the people living in several cities in southern California perform in terms of energy efficiency, such as how much electricity and n...

## The 13 Steps to Running Any Statistical Model

October 3, 2012
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All statistical modeling–whether ANOVA, Multiple Regression, Poisson Regression, Multilevel Model–is about understanding the relationship between independent and dependent variables. The content differs, but as a data analyst, you need to follow the same 13 steps to complete your modeling. This webinar will give you an overview of these 13 steps: what they are why each [...]

## A VisWeek Survival Guide, Part 2

October 3, 2012
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Less than two weeks to go until VisWeek 2012, so it’s time for the crucial second part of the survival guide. There are tons of things to see and do in Seattle, it’s easy to get distracted. Climate, Weather While the last three months have been a solid streak of sunshine, I’m told that it does rain occasionally in Seattle. Like multiple times a year. Yes, it happens. The key…

## Goldacre mine

October 3, 2012
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During a quick break between meetings, I've watched Ben Goldacre's new TED lecture. I met Ben when he gave a talk at the final conference of the Evidence project (in which I was involved), back in 2007. I like him, particularly for his wild h...

## This is an awesome paper all students in statistics should read

October 3, 2012
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The paper is a review of how to do software development for academics. I saw it via C. Titus Brown (who we have interviewed), he is also a co-author. How to write software (particularly for other people) is something that is under emphasized in many cu...

## 2-D author lists

October 3, 2012
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The order of authors on scientific papers matters a lot. The best places to be on a paper vary by field. But typically the first and the corresponding (usually last) authors are the prime real estate. When people are evaluated on the job market, for pr...

## Advice that’s so eminently sensible but so difficult to follow

October 3, 2012
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When we suggest a new method, we are duty-bound to not just demonstrate that it works better than existing approaches (or is superior in some other way such as simplicity or cost). We also need to explain why, if this new method is so great, people aren’t already using it. Various answers are possible, for [...]

## A Quick Note On Large 2D Data

October 3, 2012
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Two months ago I was told one of my old blog posts was borrowed to this post: Finding patterns in big data with SAS/GRAPH. I wrote my blog post four years ago just for fun. The over-plotting issue is pretty boring to me now, but what caught my attentio...

## Forecasting research grants

October 3, 2012
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The International Institute of Forecasters and SAS have an annual research grant scheme that has been offered for the past ten years. The amounts offered are small (a total of \$10K per year, usually split between 2 or 3 projects), but it might be usefu...

## Forecasting research grants

October 3, 2012
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The International Institute of Forecasters and SAS have an annual research grant scheme that has been offered for the past ten years.  The amounts offered are small (a total of \$10K per year, usually split between 2 or 3 projects), but it might be use...

## A Quick Note On Large 2D Data

Two months ago I was told one of my old blog posts was borrowed to this post: Finding patterns in big data with SAS/GRAPH. I wrote my blog post four years ago just for fun. The over-plotting issue is pretty boring to me now, but what caught my attention were: alpha-transparency was a new feature in SAS 9.3 (I found this hard to believe); the SAS code was so much…

## Bayesian estimation of trend with auto-regressive AR(1) deviation

October 2, 2012
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This post shows how to estimate trend coefficients when there is an auto-regressive AR(1) process on the deviation from the trend. The specific example uses a sinusoidal trend to describe daily temperatures across many years, but the programming method...

## Job!

October 2, 2012
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Faten Sabry writes: We are looking to hire full time analysts at the undergraduate and graduate levels. The work involves extensive econometric analysis and handling of large databases. The analysts will be part of a team working to address various empirical microeconomic issues. I worked with Faten and her colleagues on a consulting project once, [...]

## PhilStatLaw: Infections in the court

October 2, 2012
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Nathan Schachtman appropriately refers to the way in which “dicta infects Daubert” in his latest blogpost Siracusano Dicta Infects Daubert Decisions. Here the “dicta” (or dictum?) is a throwaway remark on (lack of) statistical significance and causal inference by the Supreme Court, in an earlier case involving the drug company Matrixx (Matrixx Initiatives, Inc. v. Siracusano). [...]

## Lostalgic: Revealing the Networked Narrative of ‘Lost’

October 2, 2012
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Lostalgic [intuitionanalytics.com], designed by Santiago Ortiz, is a comprehensive visualization tool to explore the story and characters of the popular television series Lost. Based on data scraped from the popular fan site Lostpedia, the website o...

## Inlining JAGS models in R scripts for rjags

October 2, 2012
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$Inlining JAGS models in R scripts for rjags$

JAGS (Just Another Gibbs Sampler) is a general purpose MCMC engine similar to WinBUGS and OpenBUGS. I have a slight preference for JAGS as it is free and portable, works well on Linux, and interfaces well with R. It is tempting to write a tutorial introduction to JAGS and the corresponding R package, rjags, but […]

## Open question in 1937…short SAS program today

October 2, 2012
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John D. Cook posted a story about Hardy, Ramanujan, and Euler and discusses a conjecture in number theory from 1937. Cook says, Euler discovered 635,318,657 = 158^4 + 59^4 = 134^4 + 133^4 and that this was the smallest [integer] known to be the sum of two fourth powers in [...]

## Really? A randomized trial of ‘free market’ capitalism

October 2, 2012
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This freshly published post A randomized trial of ‘free market’ capitalism – Web Exclusive Article – Significance Magazine by Michael A. Lewis at Significance today is quite interesting. It starts with a question from his social work students: doesn’t capitalism cause those who live within its confines to be more individualistic and selfish than they’d be under a different [...]

## The more statistics blogs the better

October 2, 2012
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Good friend and friend of the blog Rob Gould has started a statistics blog called Citizen Statistician. What is a citizen statistician, you ask? What is a citizen statistician? A citizen statistician participates in formal and informal data gathering....