## Methods before results

April 29, 2013
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It’s great that, in a step towards improved reproducibility, the Nature journals are removing page limits on Methods sections: To allow authors to describe their experimental designs and methods in enough detail for others to interpret and replicate them, the participating journals are removing length restrictions on Methods sections. But couldn’t they include the Methods […]

## R Is Not So Hard! A Tutorial, Part 4 (repost)

April 29, 2013
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Part 3 we used the lm() command to perform least squares regressions. In Part 4 we will look at more advanced aspects of regression models and see what R has to offer. One way of checking for non-linearity in your data is to fit a polynomial model and check whether the polynomial model fits the data better than a linear model. Or you may wish to fit a quadratic or…

## R Is Not So Hard! A Tutorial, Part 4 (repost)

April 29, 2013
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The following is not a Stats Make Me Cry original, but rather something I came across and found very useful. The article demonstrates how to examine non-linear effects (e.g. quadratic effects) using a regression model in R. If you are interested in the...

## The blogroll

April 29, 2013
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I encourage you to check out our linked blogs. Here’s what they’re all about: Cognitive and Behavioral Science BPS Research Digest: I haven’t been following this one recently, but it has lots of good links, I should probably check it more often. There are a couple things that bother me, though. The blog is sponsored [...]The post The blogroll appeared first on Statistical Modeling, Causal Inference, and Social Science.

## Figuring out the location (of the data)

April 29, 2013
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When we visualize data, we want to expose the information contained within, or to use the terminology Nate Silver popularized, to expose the signal and leave behind the noise. When graphs are not done right, sometimes they manage to obscure...

## austerity in MCMC land (#2)

April 29, 2013
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After reading the arXiv paper by Korattikara, Chen and Welling, I wondered about the expression of the acceptance step of the Metropolis-Hastings algorithm as a mean of log-likelihoods over the sample. More specifically the long sleepless nights at the hospital led me to ponder the rather silly question of the impact of replacing mean by […]

## Understanding local and global variables in the SAS/IML language

April 29, 2013
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The TV show Cheers was set in a bar "where everybody knows your name." Global knowledge of a name is appealing for a neighborhood pub, but not for a programming language. Most programming languages enable you to define functions that have local variables: variables whose names are known only inside [...]

## Slouching towards simulating investment skill

April 29, 2013
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When investment skill is simulated, it is often presented as if it is obvious how to do it.  Maybe I’m wrong, but I don’t think it’s obvious. Previously In “Simple tests of predicted returns” we saw that prediction quality need not look like what you would find in a textbook.  For example, there was a … Continue reading →

## Continuous Values and Baselines

April 29, 2013
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One of the most common mistakes people make when creating charts is to cut off the vertical axis. But why is that a problem? And what can you do when you need to show data where the amount of change is small compared to the absolute values? When we think of continuous data, we almost always think of values that have a meaningful zero. There is no question what an…

## Using the Golden Section Search Method to Minimize the Sum of Absolute Deviations

$Using the Golden Section Search Method to Minimize the Sum of Absolute Deviations$

Introduction Recently, I introduced the golden search method – a special way to save computation time by modifying the bisection method with the golden ratio – and I illustrated how to minimize a cusped function with this script.  I also wrote an R function to implement this method and an R script to apply this method […]

## MOOCs–a low-risk way to explore outside your field

April 29, 2013
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One of the things I'm realizing from Massively Open Online Courses (MOOCs) -- those online free classes from universities that have seem to sprung up from almost nowhere in the last year and a half -- is that they offer a perfect opportunity to explore...

## Sunday data/statistics link roundup (4/28/2013)

April 29, 2013
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What it feels like to be bad at math. My personal experience like this culminated in some difficulties with Green's functions back in my early days at USU. I think almost everybody who does enough math eventually runs into a … Continue reading →

## The median outclasses the mean

April 28, 2013
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The median suffers from poor marketing. All my time at school the “average” was always calculated as the arithmetic mean, by adding up all the scores and then dividing by the number of scores. When we were taught about the … Continue reading →

## Books from the Washing Machine

April 28, 2013
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Where statistics and the passion for human development meet: In a classic presentation from Hans Rosling. Who else could do this …Continue reading »

## Plain old everyday Bayesianism!

April 28, 2013
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Sam Behseta writes: There is a report by Martin Tingley and Peter Huybers in Nature on the unprecedented high temperatures at northern latitudes (Russia, Greenland, etc). What is more interesting is the authors are have used a straightforward hierarchical Bayes model, and for the first time (as far as I can remember) the results are [...]The post Plain old everyday Bayesianism! appeared first on Statistical Modeling, Causal Inference, and Social…

## The Perils of Hypothesis Testing … Again

April 28, 2013
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$The Perils of Hypothesis Testing … Again$

A few months ago I posted about John Ioannidis’ article called “Why Most Published Research Findings Are False.” Ioannidis is once again making news by publishing a similar article aimed at neuroscientists. This paper is called “Power failure: why small sample size undermines the reliability of neuroscience.” The paper is written by Button, Ioannidis, Mokrysz, […]

## Bayesian estimation of log-normal parameters

April 28, 2013
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Using the log-normal density can be confusing because it's parameterized in terms of the mean and precision of the log-scale data, not the original-scale data. Thus, if your data, y, are nicely described by a log-normal distribution, the estimated mean...

## Time-Sharing Experiments for the Social Sciences

April 27, 2013
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James Druckman and Jeremy Freese write: We are pleased to announce that Time-Sharing Experiments for the Social Sciences (TESS) was renewed for another round of funding by NSF starting last Fall. TESS allows researchers to submit proposals for experiments to be conducted on a nationally-representative, probability-based Internet platform, and successful proposals are fielded at no [...]The post Time-Sharing Experiments for the Social Sciences appeared first on Statistical Modeling, Causal Inference,…

## Getting Credit (or blame) for Something You Didn’t Do (BP oil spill, comedy hour)

April 27, 2013
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Three years ago, many of us were glued to the “spill cam” showing, in real time, the gushing oil from the April 20, 2010 explosion sinking the Deepwater Horizon oil rig in the Gulf of Mexico, killing 11, and spewing oil until July 15. Trials have been taking place this month, as people try to meet the 3 year deadline to […]

## The most cited and most butchered statistical law

April 27, 2013
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The past week, you are unable to avoid, if you read the business news, mention of the "law of large numbers". We are led to believe that tech giants like Apple and Amazon are suffering from this statistical law. For example: Apple: Newest Victim of the Law of Large Numbers (CNet) New York Times Paywall Growth Slows (Columbia Journalism Review): "Much of this is due to the law of large…

## Continued fractions!!

April 27, 2013
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Upon reading this note by John Cook on continued fractions, I wrote: If you like continued fractions, I recommend you read the relevant parts of the classic Numerical Methods That Work. The details are probably obsolete but it’s fun reading (at least, if you think that sort of thing is fun to read). I then [...]The post Continued fractions!! appeared first on Statistical Modeling, Causal Inference, and Social Science.

## Posteriors vs predictives

April 26, 2013
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Karl Saliba writes with some queries about our football paper, which I have already discussed on the blog here. He says:Thanks to the code in the appendix I could easily replicate (by using WinBUGS) a similar analysis on any football league of my ...

## Machine Learning – week 1 & 2

April 26, 2013
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This week marked the start of Coursera's highly popular Machine Learning course, taught by Coursera founder and one of Time's 2013 100 most influential people, Andrew Ng. I'm super excited to be taking this course after reading about all the cool pres...