Example 9.20: visualizing Simpson’s paradox

February 7, 2012
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Example 9.20: visualizing Simpson’s paradox

Simpson's paradox is always amazing to explain to students. What's bad for one group, and bad for another group is good for everyone, if you just collapse over the grouping variable. Unlike many mathematical paradoxes, this arises in a number of real...

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Update to Partisan Bias in Fed Inflation Forecasts

February 7, 2012
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Update to Partisan Bias in Fed Inflation Forecasts

Since I'm in the depths of PhD thesis revisions I haven't had much time to do much other than update previous posts (see my Stata Country Standardizer Update).Here is an update of an earlier post about possible partisan biases in US Federal Reserve sta...

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Think Complexity: Part Three

February 6, 2012
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Think Complexity: Part Three

My new book, Think Complexity, will be published by O'Reilly Media in March. For people who can't stand to wait that long, I am publishing excerpts here.  If you really can't wait, you can read the free version at&nbs...

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googleVis 0.2.14 is released

February 5, 2012
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googleVis 0.2.14 is released

Version 0.2.14 of the googleVis package was released on CRAN today.ChangesThe help files have been checked against changes of the Google Visualisation API, typos in the vignette have been ironed out (thanks to Pat Burns for pointing them out), a new se...

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Comparing correlations update

February 5, 2012
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Comparing correlations update

I have just published R code for calculating CIs for differences between correlations on the Serious stats book blog. This covers independent correlations (taken from chapter 6 of the book) and dependent correlations (new R code written as a suppl...

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Comparing correlations: independent and dependent (overlapping or non-overlapping)

February 5, 2012
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Comparing correlations: independent and dependent (overlapping or non-overlapping)

In Chapter 6 (correlation and covariance) I consider how to construct a confidence interval (CI) for the difference between two independent correlations.  The standard approach uses the Fisher z transformation to deal with boundary effects (the squashing of the distribution … Continue reading →

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Talk and Workshop at the Eastern Psychological Association, March 2 – 3

February 4, 2012
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Talk and Workshop at the Eastern Psychological Association, March 2 – 3

I'll be doing a talk and workshop at the meeting of the Eastern Psychological Association. Details can be found here.A list of future and past workshops can be found here.

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Serious stats – a quick chapter summary

February 4, 2012
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Serious stats – a quick chapter summary

Here is a list of the contents by chapter with quick notes on chapter content … 0. Preface (About the book; notes on software, mathematics and types of boxed sections) 1. Data, Samples and Statistics (A gentle review of measures … Continue reading →

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Implementing Circles example

February 4, 2012
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Implementing Circles example

This week I reimplemented part of Conic Sections 1 model from NetLogo. In the model turtles seek to to be in target distance from center.My code takes only one center point, so only circles can be obtained. Apart from turtle location plot giv...

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Coming R meetings in Paris

February 4, 2012
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Coming R meetings in Paris

If you live in Paris and are interested in R, there will be two meetings for you this week. First a Semin-R session, organized at the Muséum National d’Histoire Naturelle on Tuesday 7 Feb (too bad, the Museum is closed on Tuesdays). Presentations will be about colors, phylogenies and maps, while I will speak about […]

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speed of R, C, &tc.

February 2, 2012
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speed of R, C, &tc.

My Paris colleague (and fellow-runner) Aurélien Garivier has produced an interesting comparison of 4 (or 6 if you consider scilab and octave as different from matlab) computer languages in terms of speed for producing the MLE in a hidden Markov model, using EM and the Baum-Welch algorithms. His conclusions are that matlab is a lot [...]

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Serious Stats book and blog update

February 2, 2012
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Serious Stats book and blog update

This is a quick update to announce my new blog Serious Stats. This is a companion to my forthcoming book of the same name:Baguley, T. (2012, in press). Serious stats: A guide to advanced statistics for the behavioral sciences. Basingstoke: Palgrav...

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tenured research position with ABC skills!

February 2, 2012
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tenured research position with ABC skills!

I just received this announcement for the opening of a (tenured/civil servant) position in the national research institute in biostatistics, genetics, and agronomy, INRA: Position opening with profile Approximate inference techniques in complex systems Key activities and required skills: You will develop methodological research in the field of statistical inference for models used in environmental [...]

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Cochran Q Test for k related samples in R

February 1, 2012
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Cochran Q Test for k related samples in R

To run the Cochran Q Test in R, we need to download the package of it first, since it is not built-in in R. The name of the package is RVAideMemoire authored by Maxime Hervé. Here's how to do it.Codes:Here we are installing the package named RVAideMem...

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More on "A problem of significance"

February 1, 2012
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More on "A problem of significance"

A longer version of my earlier post A problem of significance just appeared in The Psychologist.Baguley, T. (2012). Can we be confident in our statistics? The Psychologist. 25, 128-9.Shortly after publication I received an email asking about statistica...

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Serious stats: A guide to advanced statistics for the behavioral sciences

February 1, 2012
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Serious stats: A guide to advanced statistics for the behavioral sciences

This is a blog to accompany my forthcoming book “Serious stats” published by Palgrave. Baguley, T. (2012, in press). Serious stats: A guide to advanced statistics for the behavioral sciences. Basingstoke: Palgrave. The book is available for pre-order (e.g., via amazon) … Continue reading →

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Are Recessions Environmentally Beneficial?

February 1, 2012
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Are Recessions Environmentally Beneficial?

Description: Total energy consumption in the United States by sector.  Vertical gray lines represent periods of recession. Data: http://www.eia.gov/totalenergy/data/annual/index.cfm#consumption http://en.wikipedia.org/wiki/List_of_rece...

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Confirming SSR, SSE, and SST using matrix in R

February 1, 2012
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The codes below was done in our regression laboratory class. Here, we run first the data in SPSS, and take the ANOVA output where we can find the computed values of SSR, SSE, and SST. #Al-Ahmadgaid Asaad#As part of the yearly report of the...

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The universal solvent of statistics

February 1, 2012
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The universal solvent of statistics

Andrew Gelman just posted an interesting article on the philosophy of Bayesian statistics. Here’s my favorite passage. This reminds me of a standard question that Don Rubin … asks in virtually any situation: “What would you do if you had all the data?” For me, that “what would you do” question is [...]

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R is the easiest language to speak badly

February 1, 2012
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R is the easiest language to speak badly

I am amazed by the number of comments I received on my recent blog entry about "by", "apply" and friends. I had started my post by pointing out that R is a language. Well indeed, I have come to the conclusion, that it is a language with lots of irregul...

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Multi-Threaded Principle Component Analysis

February 1, 2012
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Multi-Threaded Principle Component Analysis

SAS used to not support multithreading in PCA, then I figured out that its server version supports this functionality, see here. Today, I found this mutlithreading capability is finally available in PC SAS v9.22.The figure above indicates that all 4 th...

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Example: Two Sample t-Test

January 31, 2012
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The recovery time (in days) is measured for 10 patients taking a new drug and for 10 different patients taking a placebo. We wish to test the hypothesis that the mean recovery time for patients taking the drug is less than for those taking placebo. The...

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Example: One Sample t-Test

January 31, 2012
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Using the stack loss dataset, test the hypothesis that the mean of the stackloss is equal to 20 versus a two-sided alternative. Solution:Codes:Output: Interpretation: With the p-value greater than the level of significance alpha at 0.05, then we l...

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