Finding matrix elements that satisfy a logical expression

January 20, 2015
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Finding matrix elements that satisfy a logical expression

A common task in SAS/IML programming is finding elements of a SAS/IML matrix that satisfy a logical expression. For example, you might need to know which matrix elements are missing, are negative, or are divisible by 2. In the DATA step, you can use the WHERE clause to subset data. […]

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Communicating Risk and Uncertainty

January 20, 2015
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Communicating Risk and Uncertainty

David Spiegelhalter gave a fascinating talk on Communicating Risk and Uncertainty to the Public & Policymakers at the Grantham Institute of the Imperial College in London last Tuesday.In a very engaging way David gave many examples and anecdotes fr...

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Workshop on science communication for graduate students

January 19, 2015
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Nathan Sanders writes: Applications are now open for the Communicating Science 2015 workshop (http://comscicon.com/apply-comscicon15), to be held in Cambridge, MA on June 18-20th, 2015. Graduate students at US institutions in all fields of science and engineering are encouraged to apply. The application will close on March 1st. Acceptance to the workshop is competitive; attendance of […] The post Workshop on science communication for graduate students appeared first on Statistical Modeling,…

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“Surely our first response to the disproof of a shocking-but-surprising claim should be to be un-shocked and un-surprised, not to try to explain away the refutation”

January 19, 2015
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“Surely our first response to the disproof of a shocking-but-surprising claim should be to be un-shocked and un-surprised, not to try to explain away the refutation”

I came across the above quote the other day in an old post of mine, when searching for a Schrodinger’s cat image. The quote came up in the context of a statistical claim made by a political activist which was widely promoted and discussed but which turned out to be false. As I wrote at […] The post “Surely our first response to the disproof of a shocking-but-surprising claim should…

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On deck this week

January 19, 2015
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Mon: “Surely our first response to the disproof of a shocking-but-surprising claim should be to be un-shocked and un-surprised, not to try to explain away the refutation” Tues: Another benefit of bloglag Wed: High risk, low return Thurs: Patience and research Fri: This is why I’m a political scientist and not a psychologist Sat: “What […] The post On deck this week appeared first on Statistical Modeling, Causal Inference, and…

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Haavelmo and Causal Modeling

January 19, 2015
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Speaking of causal modeling, as we were in a recent post, Econometric Theory is doing a special issue on Haavelmo. (This is not new information, but hey, I'm usually slow to notice things, and perhaps you are too.) Should be a fine issue...

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DIA Joint Adaptive Design and Bayesian Statistics Conference

January 19, 2015
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This is my first real contribution to the ISBA Section on Biostatistics and Pharmaceutical Statistics, in my new role of secretary. Our section has formally endorsed this very interesting conference $-$ the timeline is very short, as the conferenc...

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Power Analysis and Non-Replicability: If bad statistics is prevalent in your field, does it follow you can’t be guilty of scientific fraud?

January 19, 2015
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Power Analysis and Non-Replicability: If bad statistics is prevalent in your field, does it follow you can’t be guilty of scientific fraud?

If questionable research practices (QRPs) are prevalent in your field, then apparently you can’t be guilty of scientific misconduct or fraud (by mere QRP finagling), or so some suggest. Isn’t that an incentive for making QRPs the norm?  The following is a recent blog discussion (by  Ulrich Schimmack) on the Jens Förster scandal: I thank Richard Gill for […]

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Why Is Paper-Writing Software So Awful?

January 19, 2015
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The tools of the trade for academics and others who write research papers are among the worst software has to offer. Whether it’s writing or citation management, there are countless issues and annoyances. How is it possible that this fairly straightforward category of software is so outdated and awful? Microsoft Word The impetus for this … Continue reading Why Is Paper-Writing Software So Awful?

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Lee Sechrest

January 18, 2015
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Lee Sechrest

Yesterday we posted on Lewis Richardson, a scientist who did pioneering work in weather prediction and, separately, in fractals, in the early twentieth century. I was pointed to Richardson by Lee Sechrest, who I then googled. Here’s Sechrest’s story: His first major book [was] “Psychotherapy and the Psychology of Behavior Change” . . . Sechrest […] The post Lee Sechrest appeared first on Statistical Modeling, Causal Inference, and Social Science.

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Multiple Comparisons with BayesFactor, Part 2 – order restrictions

January 18, 2015
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Multiple Comparisons with BayesFactor, Part 2 – order restrictions

In my previous post, I described how to do multiple comparisons using the BayesFactor package. Part 1 concentrated on testing equality constraints among effects: for instance, that the the effects of two factor levels are equal, while leaving the third free to be different. In this second part, I will describe how to test order restrictions on factor level effects. This post will be a little more involved than the…

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SAS PROC MCMC example in R: Logistic Regression Random-Effects Model

January 18, 2015
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In this post I will run SAS example Logistic Regression Random-Effects Model in four R based solutions; Jags, STAN, MCMCpack and LaplacesDemon. To quote the SAS manual: 'The data are taken from Crowder (1978). The Seeds data set is a 2 x 2 fa...

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Multiple Comparisons with BayesFactor, Part 1

January 17, 2015
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Multiple Comparisons with BayesFactor, Part 1

One of the most frequently-asked questions about the BayesFactor package is how to do multiple comparisons; that is, given that some effect exists across factor levels or means, how can we test whether two specific effects are unequal. In the next two posts, I'll explain how this can be done in two cases: in Part 1, I'll cover tests for equality, and in Part 2 I'll cover tests for specific…

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R bracket is a bit irregular

January 17, 2015
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R bracket is a bit irregular

While skimming Professor Hadley Wickham’s Advanced R I got to thinking about nature of the square-bracket or extract operator in R. It turns out “[,]” is a bit more irregular than I remembered. The subsetting section of Advanced R has a very good discussion on the subsetting and selection operators found in R. In particular … Continue reading R bracket is a bit irregular → Related posts: R annoyances Selection…

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Lewis Richardson, father of numerical weather prediction and of fractals

January 17, 2015
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Lewis Richardson, father of numerical weather prediction and of fractals

Lee Sechrest writes: If you get a chance, Wiki this guy: I [Sechrest] did and was gratifyingly reminded that I read some bits of his work in graduate school 60 years ago. Specifically, about his math models for predicting wars and his work on fractals to arrive at better estimates of the lengths of common […] The post Lewis Richardson, father of numerical weather prediction and of fractals appeared first…

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Free introduction to doing Bayesian data analysis – Share with friends!

January 16, 2015
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Free introduction to doing Bayesian data analysis – Share with friends!

The goal of Chapter 2 is to introduce the conceptual framework of Bayesian data analysis. Bayesian data analysis has two foundational ideas. The first idea is that Bayesian inference is reallocation of credibility across possibilities. The second found...

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Free introduction to doing Bayesian data analysis – Share with friends!

January 16, 2015
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Free introduction to doing Bayesian data analysis – Share with friends!

The goal of Chapter 2 is to introduce the conceptual framework of Bayesian data analysis. Bayesian data analysis has two foundational ideas. The first idea is that Bayesian inference is reallocation of credibility across possibilities. The second found...

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If you were going to write a paper about the false discovery rate you should have done it in 2002

January 16, 2015
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If you were going to write a paper about the false discovery rate you should have done it in 2002

People often talk about academic superstars as people who have written highly cited papers. Some of that has to do with people's genius, or ability, or whatever. But one factor that I think sometimes gets lost is luck and timing. So I wrote a little script to get the first 30 papers that appear when

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When a study fails to replicate: let’s be fair and open-minded

January 16, 2015
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In a recent discussion of replication in science (particularly psychology experiments), the question came up of how to interpret things when a preregistered replication reaches a conclusion different from the original study. Typically the original, published result is large and statistically significant, and the estimate from the replication is small and not statistically significant. One […] The post When a study fails to replicate: let’s be fair and open-minded appeared…

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Cross-validation, LOO and WAIC for time series

January 16, 2015
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This post is by Aki. Jonah asked in Stan users mailing list Suppose we have J groups and T time periods, so y[t,j] is the observed value of y at time t for group j. (We also have predictors x[t,j].) I’m wondering if WAIC is appropriate in this scenario assuming that our interest in predictive accuracy is for […] The post Cross-validation, LOO and WAIC for time series appeared first on Statistical Modeling,…

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A Sensitive Approach to Risk and Screening

January 15, 2015
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A Sensitive Approach to Risk and Screening

Risk is an important topic In order to make informed decisions about screening and medical interventions, people need to have a good understanding of risk and probability. The communication and understanding of risk was a very popular topic at the … Continue reading →

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A Sensitive Approach to Risk and Screening

January 15, 2015
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A Sensitive Approach to Risk and Screening

Risk is an important topic In order to make informed decisions about screening and medical interventions, people need to have a good understanding of risk and probability. The communication and understanding of risk was a very popular topic at the … Continue reading →

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The bracket!

January 15, 2015
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The bracket!

That’s right, we’re getting ready for the battle to choose the ultimate seminar speaker. Paul Davidson, who sent in the image below, writes: Knocked together in Excel. I’m European, so I may not have respected the North American system for brackets i.e. I split each category into seeded pools and randomly drew from them. The […] The post The bracket! appeared first on Statistical Modeling, Causal Inference, and Social Science.

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