## Knowledge in the chart and knowledge in the head

February 25, 2014
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One of the many insights from Don Norman's great design book is that a user's behavior is affected by "knowledge in the world", and "knowledge in the head." Applied to graphics, this means readers of graphics use both knowledge in...

## Mathematica: Introducing the Wolfram Language

February 25, 2014
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Finally, here it is, check out the video below as Stephen Wolfram showcases the Wolfram language, From my previous post, I said that I used Wolfram Mathematica for about a year before I embrace R. And frankly, I've been in love with Mathematica; it nev...

## Next Kölner R User Meeting: 26 February 2014

February 25, 2014
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The next Cologne R user group meeting is scheduled for tomorrow, 26 February 2014. We are delighted to welcome:Diego de Castillo: R and databasesKim Kuen Tang: Hands on using R and kdb+ togetherFrank Celler: ArangoDB (Lightning Talk)Further details an...

## LaTeX: How to install TeX Live – qtree package in Ubuntu 12.10

February 25, 2014
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There is a question on TeX - StackExchange that has no direct solution to the installation of the qtree - TeX Live package in Ubuntu. And I want to answer that in this post, then just drop the link of this article to the comment section of the said que...

## Job Trends in the Analytics Market: New, Improved, now Fortified with C, Java, MATLAB, Python, Julia and Many More!

February 25, 2014
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I’m expanding the coverage of my article, The Popularity of Data Analysis Software. This is the first installment, which includes a new opening and a greatly expanded analysis of the analytics job market. Here it is, from the abstract onward … Continue reading →

## The forecast mean after back-transformation

February 25, 2014
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Many functions in the forecast package for R will allow a Box-Cox transformation. The models are fitted to the transformed data and the forecasts and prediction intervals are back-transformed. This preserves the coverage of the prediction intervals, and the back-transformed point forecast can be considered the median of the forecast densities (assuming the forecast densities on the transformed scale are symmetric). For many purposes, this is acceptable, but occasionally the…

## Bayesian First Aid: Two Sample t-test

February 24, 2014
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As spring follows winter once more here down in southern Sweden, the two sample t-test follows the one sample t-test. This is a continuation of the Bayesian First Aid alternative to the one sample t-test where I’ll introduce the two sample alternat...

## Dancing Statistics: Communicating Psychology to the Public through Dance

February 24, 2014
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Do you know what correlation, variance, frequency distributions, sampling and standard errors are? If not, you now have to chance to learn each of these statistical concepts via the medium of... modern dance. Initiated by Lucy Irving (Middlesex Unive...

## The Kernel of Truth in Frequentism: The Pros and Cons of this Special Case

February 24, 2014
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The previous three posts demonstrated how frequencies are a special case of more general Bayesian methods. This final post will consider the strengths and weaknesses of this special case by addressing three cons and two pros. Con 1: This special case e...

## “Edlin’s rule” for routinely scaling down published estimates

February 24, 2014
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A few months ago I reacted (see further discussion in comments here) to a recent study on early childhood intervention, in which researchers Paul Gertler, James Heckman, Rodrigo Pinto, Arianna Zanolini, Christel Vermeerch, Susan Walker, Susan M. Chang, and Sally Grantham-McGregor estimated that a particular intervention on young children had raised incomes on young adults […]The post “Edlin’s rule” for routinely scaling down published estimates appeared first on Statistical Modeling,…

## On deck this week

February 24, 2014
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Mon: “Edlin’s rule” for routinely scaling down published estimates Tues: Basketball Stats: Don’t model the probability of win, model the expected score differential Wed: A good comment on one of my papers Thurs: “What Can we Learn from the Many Labs Replication Project?” Fri: God/leaf/tree Sat: “We are moving from an era of private data […]The post On deck this week appeared first on Statistical Modeling, Causal Inference, and Social…

## Update on Dataviz Workshop 2

February 24, 2014
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The class practised doing critiques on the famous Wind Map by Fernanda Viegas and Martin Wattenberg. Click here for a real-time version of the map. I selected this particular project because it is a heartless person indeed who does not...

## Numbersense and true lies

February 24, 2014
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Long before I came up with "numbersense," I wrote about "true lies" in data analysis. (link) The nature of data, especially Big (as in multidimensional) Data, is that one can come up with an infinite number of statistical computations, all of which are "true" in the sense that one would obtain such statistics were one to plug the data into textbook formulas. Inevitably, some of these statistics lead to contradictions.…

## More on Factor-Augmented VAR’s (Principal Components Regression)

February 24, 2014
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Here's a sampling of emails that I received on my recent "Factor-Augmented VAR" post.Serena Ng at Columbia notes that her "Targeted Predictors" paper (with Jushan Bai) is motivated by considerations similar to those that motivate partial least squares ...

## Three ways to add a smoothing spline to a scatter plot in SAS

February 24, 2014
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Like many SAS programmers, I use the Statistical Graphics (SG) procedures to graph my data in SAS. To me, the SGPLOT and SGRENDER procedures are powerful, easy to use, and produce fabulous ODS graphics. I was therefore surprised when a SAS customer told me that he continues to use the [...]

## BayesFactor update: 0.9.7.

February 24, 2014
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BayesFactor version 0.9.7 has been released to CRAN. It does have a few bug fixes, so update soon. A list of changes can be found in the NEWS file.

## Bayes factor t tests, part 2: Two-sample tests

February 23, 2014
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In the previous post, I introduced the logic of Bayes factors for one-sample designs by means of a simple example. In this post, I will give more detail about the models and assumptions used by the BayesFactor package, and also how to do simple analyses of two- sample designs.See the previous posts for background:What is a Bayes factor?Bayes factor t tests, part 1This article will cover two-sample t tests.Bayesian t…

## Statistical politicians

February 23, 2014
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Last week we had the pleasure of Professor Stephen Pollock (University of Leicester) visiting our Department, best known in academic circles for his work on time series filtering (see his papers, and his excellent book). But he has another career as a member of the UK House of Lords (under the name Viscount Hanworth — he is a hereditary peer). It made me wonder how many other politicians have PhDs…

## Arnold’s "Signature"

February 23, 2014
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Anonymity is part of the culture when it comes to refereeing papers submitted for possible publication in economics, econometrics, and statistics. Referees' names are typically "blinded", and some journals use a "double-blind" process, so that authors ...

## Teach students to learn to fish

February 23, 2014
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There is a common saying that goes roughly, “Give a person a fish and you feed him for a day. Teach a person to fish and you feed her for a lifetime.” Statistics education is all about teaching people to … Continue reading →

## Teach students to learn to fish

February 23, 2014
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There is a common saying that goes roughly, “Give a person a fish and you feed him for a day. Teach a person to fish and you feed her for a lifetime.” Statistics education is all about teaching people to … Continue reading →

## Parallel Monte Carlo using Scala

February 23, 2014
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$Parallel Monte Carlo using Scala$

Introduction In previous posts I have discussed general issues regarding parallel MCMC and examined in detail parallel Monte Carlo on a multicore laptop. In those posts I used the C programming language in conjunction with the MPI parallel library in order to illustrate the concepts. In this post I want to take the example from […]

## Parallel Monte Carlo using Scala

February 23, 2014
By
$Parallel Monte Carlo using Scala$

Introduction In previous posts I have discussed general issues regarding parallel MCMC and examined in detail parallel Monte Carlo on a multicore laptop. In those posts I used the C programming language in conjunction with the MPI parallel library in order to illustrate the concepts. In this post I want to take the example from […]