Roller poster

September 23, 2015
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Roller poster

Last week, Anna was at the "Autumn Meeting on Latent Gaussian Models" in Trondheim (Norway), where she presented our work on using INLA to estimate the Expected Value of Partial Perfect Information (EVPPI) in health economic evaluation (here'...

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Statistical rivulets: Who wrote this?

September 23, 2015
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Statistical rivulets: Who wrote this?

[I]t seems to be useful for statisticians generally to engage in retrospection at this time, because there seems now to exist an opportunity for a convergence of view on the central core of our subject. Unless such an opportunity is taken there is a danger that the powerful central stream of development of our subject […]

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Launch(ed)

September 22, 2015
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Launch(ed)

Today I spoke at the LSHTM Symposium on Stepped Wedge Trials about our work on sample size calculations based on simulations $-$ it was organised to officially "launch" our series of papers in Trials.I think it was a very good event, with lot...

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The Solution

September 22, 2015
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The Solution

You can find a solution to the problem posed in yesterday's post here.I hope you can read my writing!p.s.: Dan Getz kindly supplied a LaTeX version - here's the pdf file. Thanks, Dan!© 2015, David E. Giles

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Statistics and Data Science

September 22, 2015
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Statistics and Data Science

Recently I was referred to a nice article talking about the relationship between Statistics and data science. Here is my feedback to share with you: First of all, Statistics is a science dealing with data, including three main components,  data preparation (storage, reading, organization, cleaning), exploratory data analysis (numerical summarization, visualization), and statistical inference (frequentist […]

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Statistics and Data Science

September 22, 2015
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Statistics and Data Science

Recently I was referred to a nice article talking about the relationship between Statistics and data science. Here is my feedback to share with you: First of all, Statistics is a science dealing with data, including five main components,  data collection (design of experiment, sampling), data preparation (storage, reading, organization, cleaning), exploratory data analysis (numerical summarization, […]

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PK/PD Talk with Stan — Thu 8 Oct, 10:30 AM at Columbia: Improved confidence intervals and p-values by sampling from the normalized likelihood

September 22, 2015
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Sebastian Ueckert and France Mentré are swinging by to visit the Stan team at Columbia and Sebastian’s presenting the following talk, to which everyone is invited. Improved confidence intervals and p-values by sampling from the normalized likelihood Sebastian Ueckert (1,2), Marie-Karelle Riviere (1), France Mentré (1) (1) IAME, UMR 1137, INSERM and University Paris Diderot, […] The post PK/PD Talk with Stan — Thu 8 Oct, 10:30 AM at Columbia:…

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How do you know if your model is going to work?

September 22, 2015
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How do you know if your model is going to work?

Authors: John Mount (more articles) and Nina Zumel (more articles). Our four part article series collected into one piece. Part 1: The problem Part 2: In-training set measures Part 3: Out of sample procedures Part 4: Cross-validation techniques “Essentially, all models are wrong, but some are useful.” George Box Here’s a caricature of a data … Continue reading How do you know if your model is going to work?

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Parsing a large amount of characters into a POSIXct object

September 22, 2015
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When trying to parse a large amount of datetime characters into POSXIct objects, it struck me that strftime and as.POSIXct where actually quite slow. When using the parsing functions from lubridate, these where a lot faster. The following benchmark shows… See more ›

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“I do not agree with the view that being convinced an effect is real relieves a researcher from statistically testing it.”

September 22, 2015
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Florian Wickelmaier writes: I’m writing to tell you about my experiences with another instance of “the difference between significant and not significant.” In a lab course, I came across a paper by Costa et al. [Cognition 130 (2) (2014) 236-254 (http://dx.doi.org/10.1016/j.cognition.2013.11.010). In several experiments, they compare the effects in two two-by-two tables by comparing the […] The post “I do not agree with the view that being convinced an effect…

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Round-up of up-coming events

September 22, 2015
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I finally got around to updating the event listings. In the coming months, I will be giving a number of talks on data visualization. Next week, I will be speaking to the Data Visualization New York meetup, ably organized by...

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Propublica is on a roll

September 22, 2015
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Really enjoying Propublica pieces lately. There are several articles about topics of great interest to me, and those who read my books will be familiar with these themes. My favorite is an article that speaks a truth about data projects -- much as we sweat about data collection, data integrity and statistical models, the true challenge is in persuading the rest of the world to adopt our endproducts. The title…

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What’s the Difference Between Data Science and Statistics?

September 22, 2015
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What’s the Difference Between Data  Science and Statistics?

From: https://www.udemy.com/data-science/#articleNot long ago, the term "data science" meant nothing to most people -- even the those who worked in data. A likely response to the term was: "Isn't that just statistics?".These days, data science is ...

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Upcoming talks in California

September 22, 2015
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Upcoming talks in California

I’m back in California for the next couple of weeks, and will give the following talk at Stanford and UC-Davis. Optimal forecast reconciliation for big time series data Time series can often be naturally disaggregated in a hierarchical or grouped structure. For example, a manufacturing company can disaggregate total demand for their products by country of […]

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Notes from the Kölner R meeting, 18 September 2015

September 22, 2015
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Notes from the Kölner R meeting, 18 September 2015

Last Friday the Cologne R user group came together for the 15th time. Since its inception over three years ago the group evolved from a small gathering in a pub into an active data science community, covering wider topics than just R. Still, R is the l...

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How do you know if your model is going to work? Part 4: Cross-validation techniques

September 21, 2015
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How do you know if your model is going to work? Part 4: Cross-validation techniques

Authors: John Mount (more articles) and Nina Zumel (more articles). In this article we conclude our four part series on basic model testing. When fitting and selecting models in a data science project, how do you know that your final model is good? And how sure are you that it’s better than the models that … Continue reading How do you know if your model is going to work? Part…

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Try This Problem

September 21, 2015
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Try This Problem

Here's a little exercise for you to work on:We know from the Gauss-Markhov Theorem that within the class of linear and unbiased estimators, the OLS estimator is most efficient. Because it is unbiased, it therefore has the smallest possible Mean Squared...

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Have weak data. But need to make decision. What to do?

September 21, 2015
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Vlad Malik writes: I just re-read your article “Of Beauty, Sex and Power”. In my line of work (online analytics), low power is a recurring, existential problem. Do we act on this data or not? If not, why are we even in this business? That’s our daily struggle. Low power seems to create a sort […] The post Have weak data. But need to make decision. What to do? appeared…

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Statbusters: What the experiments on rigging elections via Google tell us

September 21, 2015
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For this week's Statbusters (link), we opine on that astounding report from a few weeks ago about how Google could manipulate the next elections by biasing search results. We walk you through our vetting process, starting with face validity ("the magnitude of the reported effect is too large to be believed!"). The crux of the article is about the experimental design. You start with a group of people who have…

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Making stuff up to get published in NYTimes

September 21, 2015
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Making stuff up to get published in NYTimes

Reader/friend Tom B. knows about my interest in grade "deflation" policies, and proceeds to ruin my breakfast by sending me a link to this ludicrous "letter to the editor" by a high-school counsellor (link). It starts with a made-up assertion: As the new academic term starts, I’m rooting for this to be the year when students start getting the grades they rightfully earn without high schools and colleges manipulating numbers…

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On deck this week

September 21, 2015
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Mon: Have weak data. But need to make decision. What to do? Tues: “I do not agree with the view that being convinced an effect is real relieves a researcher from statistically testing it.” Wed: Optimistic or pessimistic priors Thurs: Draw your own graph! Fri: Low-power pose Sat: Annals of Spam Sun: The Final Bug, […] The post On deck this week appeared first on Statistical Modeling, Causal Inference, and…

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Nice title but dubious message

September 21, 2015
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Nice title but dubious message

I like to uaeuse declarative titles for charts. This chart below, found in an investment magazine published by Charles Schwab, wants to tell us that emerging markets "perform differently." That is a nice concise message. Now, what does the chart...

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International Symposium on Forecasting: Spain 2016

September 21, 2015
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International Symposium on Forecasting: Spain 2016

June 19-22, 2016 Santander, Spain – Palace of La Magdalena The International Symposium on Forecasting (ISF) is the premier forecasting conference, attracting the world’s leading forecasting researchers, practitioners, and students. Through a combination of keynote speaker presentations, academic sessions, workshops, and social programs, the ISF provides many excellent opportunities for networking, learning, and fun. Speakers: […]

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