## An inspired picture of Blackberry’s dying inspiration

September 30, 2013
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The New York Times has a splendid example of an infographics this weekend, showing the rise and fall of the Blackberry. Notice the inspired touch of the black circles to trace the outline of Blackberry's market share. They are a...

## Generate combinations in SAS

September 30, 2013
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Last week I described how to generate permutations in SAS. A related concept is the "combination." In probability and statistics, a combination is a subset of k items chosen from a set that contains N items. Order does not matter, so although the ordered triplets (B, A, C) and (C, [...]

## R Presentation

September 30, 2013
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Last week a preview of version 0.98 of R Studio  was released, with lots of new features, including some useful debugging tools. Also part of the release was a new option for creating presentations, which looks like it will be very useful. The presen...

## Estimating Undirected Graphs Under Weak Assumptions

September 30, 2013
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$Estimating Undirected Graphs Under Weak Assumptions$

Mladen Kolar, Alessandro Rinaldo and I have uploaded a paper to arXiv entitled “Estimating Undirected Graphs Under Weak Assumptions.” As the name implies, the goal is to estimate an undirected graph from random vectors . Here, each is a vector with coordinates, or features. The graph has nodes, one for each feature. We put an […]

## Estimating Undirected Graphs Under Weak Assumptions

September 30, 2013
By
$Estimating Undirected Graphs Under Weak Assumptions$

Mladen Kolar, Alessandro Rinaldo and I have uploaded a paper to arXiv entitled “Estimating Undirected Graphs Under Weak Assumptions.” As the name implies, the goal is to estimate an undirected graph from random vectors . Here, each is a vector with coordinates, or features. The graph has nodes, one for each feature. We put an […]

## Testing R Packages

September 30, 2013
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This guy th3james claimed Testing Code Is Simple, and I agree. In the R world, this is not anything new. As far as I can see, there are three schools of R users with different testing techniques: tests are put under package/tests/, and a foo-test.Rou...

## Highly probable vs highly probed: Bayesian/ error statistical differences

September 29, 2013
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A reader asks: “Can you tell me about disagreements on numbers between a severity assessment within error statistics, and a Bayesian assessment of posterior probabilities?” Sure. There are differences between Bayesian posterior probabilities and formal error statistical measures, as well as between the latter and a severity (SEV) assessment, which differs from the standard type […]

## Those who can, teach statistics

September 29, 2013
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The phrase I despise more than any in popular use (and believe me there are many contenders) is “Those who can, do, and those who can’t, teach.” I like many of the sayings of George Bernard Shaw, but this one … Continue reading →

## Sunday data/statistics link roundup (9/29/13)

September 29, 2013
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The links are back! Read on. Susan Murphy - a statistician - wins a Macarthur Award. Great for the field of statistics (via Dan S. and Simina B., among others). Related: an Interview with David Donoho about the Shaw Prize. Statisticians are … Continue reading →

## The difficulties of measuring just about anything

September 29, 2013
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Mark Duckenfield writes: Some comments on statistics and “bad math”, that I think display a clear misunderstanding of statistics and surveys. http://www.armytimes.com/article/20130714/NEWS/307140016/Marine-officer-Scope-sex-assault-problem-exaggerated and the editorial to which it refers http://online.wsj.com/article/SB10001424127887323582904578484941173658754.html The original report is quite clear about weighting things, smaple sizes, etc. The apparent “clincher” argument in the editorial—that over 50% of unwanted sexual advances […]The post The difficulties of measuring just about anything appeared first on Statistical Modeling, Causal…

## Mixed Models: Influence in Heterogeneous Variance Model

September 29, 2013
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In this post I extend my knowledge of mixed models by redoing section 59.7 (page 5048) of the SAS/STAT user guide. I don't think this particular example can be run in lme4, so that leaves nlme and MCMCglmm. MCMCglmm has less ability for influence measu...

## Parallel tempering and Metropolis coupled MCMC

September 29, 2013
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$Parallel tempering and Metropolis coupled MCMC$

Introduction Parallel tempering is a method for getting Metropolis-Hastings based MCMC algorithms to work better on multi-modal distributions. Although the idea has been around for more than 20 years, and works well on many problems, it still isn’t routinely used in applications. I think this is partly because relatively few people understand how it works, […]

## Parallel tempering and Metropolis coupled MCMC

September 29, 2013
By
$Parallel tempering and Metropolis coupled MCMC$

Introduction Parallel tempering is a method for getting Metropolis-Hastings based MCMC algorithms to work better on multi-modal distributions. Although the idea has been around for more than 20 years, and works well on many problems, it still isn’t routinely used in applications. I think this is partly because relatively few people understand how it works, […]

## Le Monde puzzle [#835]

September 28, 2013
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The current puzzle is apparently suffering from combinatoric complexity : N persons (with 20≤N≤23) are sitting around a round table and everyone has a green or red token. Both colours are represented. First, each player with a red token take the token of the player immediately to her or his left. Second, each player with […]

## IMAODBC 2013: And the winner is …

September 28, 2013
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The Best-Presentation Award of the International Marketing and Output Database Conference IMAODBC 2013 in Neuchâtel/Switzerland goes to Ilka Willand from the  German …Continue reading »

## Difficulties of using statistical significance (or lack thereof) to sift through and compare research hypotheses

September 28, 2013
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Dean Eckles writes: Thought you might be interested in an example that touches on a couple recurring topics: 1. The difference between a statistically significant finding and one that is non-significant need not be itself statistically significant (thus highlighting the problems of using NHST to declare whether an effect exists or not). 2. Continued issues […]The post Difficulties of using statistical significance (or lack thereof) to sift through and compare…

## Local Search and The Probability of Failure

September 28, 2013
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Infogroup - one of the leading providers of business listings - has an interesting post on their site about the problem of errors in local data. In this article they talk specifically about the error of business closure and the...

## Announcing Statistics with Interactive R Learning Software Environment

September 27, 2013
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Editor's note: This post was written by Nick Carchedi, a Master's degree student in the Department of Biostatistics at Johns Hopkins. He is working with us to develop software for interactive learning of R and statistics.  Inspired by the relative … Continue reading →

## Setting up Jitts online

September 27, 2013
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I use just-in-time teaching assignments in all my classes now. Vince helpfully sent along these instructions for setting these up on Google. See below. I think Jitts are just wonderful, and they’re so easy to set up, you should definitely be doing them in your classes too. I’ve had more difficulty with Peer Instruction (the […]The post Setting up Jitts online appeared first on Statistical Modeling, Causal Inference, and Social…

## Blog Contents: August 2013

September 27, 2013
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August 2013 (8/1) Blogging (flogging?) the SLP: Response to Reply- Xi’an Robert (8/5) At the JSM: 2013 International Year of Statistics (8/6) What did Nate Silver just say? Blogging the JSM (8/9) 11th bullet, multiple choice question, and last thoughts on the JSM (8/11) E.S. Pearson: “Ideas came into my head as I sat on […]

## Logistic regression and categorical covariates

September 27, 2013
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$A$

A short post to get back – for my nonlife insurance course – on the interpretation of the output of a regression when there is a categorical covariate. Consider the following dataset > db = read.table("http://freakonometrics.free.fr/db.txt",header=TRUE,sep=";") > attach(db) > tail(db) Y X1 X2 X3 995 1 4.801836 20.82947 A 996 1 9.867854 24.39920 C 997 1 5.390730 21.25119 D 998 1 6.556160 20.79811 D 999 1 4.710276 21.15373 A 1000…

## OTexts.org is launched

September 26, 2013
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The publishing platform I set up for my forecasting book has now been extended to cover more books and greater functionality. Check it out at www.otexts.org. So far, we have three complete books: Forecasting: principles and practice, by Rob J Hyndman and George Athanasopoulos Statistical foundations of machine learning, by Gianluca Bontempi and Souhaib Ben Taieb Modal logic of strict necessity and possbibility, by Evgeni Latinov and one book currently…

## How could code review discourage code disclosure? Reviewers with motivation.

September 26, 2013
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A piece appeared a couple of days ago in Nature describing Mozilla's efforts to implement code review for scientific papers. As anyone who follows our blog knows, we are in favor of reproducible research, in favor of disclosing code, and … Continue reading →