May 23, 2013
By

Andrew Sullivan links to Maureen O'Connor (link) who picked up on Netflix's recent advertising pitch mischievously titled "Netflix adultery". Andrew highlighted this statistical result, with Maureen's interpretation, supposedly sourced from Netflix although I wasn't able to find the actual study. (I added the emphasis.) In a study of 2000 American adults, 12 percent confessed to watching ahead on TV shows they were supposed to save to watch with their partners.…

## Bayes Pharma 2013 (3)

May 22, 2013
By

Another very interesting day. The highlight of the morning was, in my opinion, David Ohlssen's talk. David is with Novartis US and has discussed a few issues related with subgroup analysis, pointing out the potential strengths of applying a Bayesian ap...

## To Throw Away Data: Plagiarism as a Statistical Crime

May 22, 2013
By

I’ve been blogging a lot lately about plagiarism (sorry, Bob!), and one thing that’s been bugging me is, why does it bother me so much. Part of the story is simple: much of my reputation comes from the words I write, so I bristle at any attempt to devalue words. I feel the same way [...]The post To Throw Away Data: Plagiarism as a Statistical Crime appeared first on Statistical…

## Timing performance improvements due to vectorization

May 22, 2013
By

Last week I discussed a program that had three nested loops that used scalar operations in the innermost loop. I mentioned that this program was not vectorized, and would therefore be slow in a matrix language such as SAS/IML, MATLAB, or R. I then went through a series of steps [...]

## Bayes Pharma 2013 (2)

May 21, 2013
By

The first day of the conference was quite good, I thought. I was pleased with the audience's response to my talk and also the other talks were quite good. The level is even higher than last year. There are about 75 people attending (which is ...

## Hospital Rates: Comparing Hospital Costs versus their Mortality Rate

May 21, 2013
By

Is your local (U.S.) hospital more expensive than others? And how does its mortality rate stack up against others? Hospital Costs [kitware.com] developed by visualization and imaging company Kitware, contrasts statistics about hospital-specific char...

## 30 Years of "Oxford Summer Eight" Rowing Boat Bump Races

May 21, 2013
By

The interactive visualization Men's Eights 1980 - 2012 [feathersquare.com] by Feather and Square provides a complete overview of the "Oxford Summer Eight" bump race results. Individual teams can be selected to explore their historical performance be...

## Recently in the sister blog

May 21, 2013
By

The end of Michelle Rhee. The relevance of statisticians to researchers in different fields of social science. Regression discontinuity. Free expression vs. not wanting to make anyone personally uncomfortable. Political coalitions are diverse (and there’s no use pretending otherwise). According to David Brooks, staying out of jail is a conservative value. I’ve heard of the [...]The post Recently in the sister blog appeared first on Statistical Modeling, Causal Inference, and…

## Lose the base, connect the dot, and confuse the message

May 21, 2013
By

Reader Jack S. sent over this chart (link): The first problem readers encounter with this image is "What is MMI?" I like to think of any presentation as a set of tearout pages. Even if the image is part of...

## Slide: one function for lag/lead variables in data frames, including time-series cross-sectional data

May 21, 2013
By

I often want to quickly create a lag or lead variable in an R data frame. Sometimes I also want to create the lag or lead variable for different groups in a data frame, for example, if I want to lag GDP for each country in a data frame. I've found ...

## An R debugging example

May 21, 2013
By

The steps taken to fix an R problem. Task To prepare for the Portfolio Probe blog post called “Implied alpha and minimum variance”, I tried to update a matrix of daily stock prices using a function I had written for the purpose. Error When I tried to do what I wanted, I got: > univclose130518 […] The post An R debugging example appeared first on Burns Statistics.

## Don’t be misguided by the beauty of mathematics, if the data tells you otherwise

May 21, 2013
By

I was trained as a mathematician and it was only last year, when I attended the Royal Statistical Society conference and met many statisticians that I understood how different the two groups are. In mathematics you often start with some axioms, things...

## Bayes Pharma 2013 (1)

May 20, 2013
By

Earlier today, I've arrived in Rotterdam for the Bayes Pharma conference. As I already said in a previous post, I think we have quite an exciting line up. In fact, I think that the finalised programme is packed with interesting talks!My first impressio...

## R/Finance 2013 slides

May 20, 2013
By

I have just returned from the R/Finance conference and want to share with you my slides and examples. The Cluster Risk Parity portfolio allocation method is an example of Cluster Portfolio Allocation methods that focuses on diversification or more specifically diversification of your risk bets. (i.e. portfolio that distributes risk equally both within clusters and […]

## More on Chutes & Ladders

May 20, 2013
By

Matt Maenner asked about the sawtooth pattern in the figure in my last post on Chutes & Ladders. Damn you, Matt! I thought I was done with this. Don’t feed my obsession. My response was that if the game ends early, it’s even more likely that it’ll be the kid who went first who won. […]

## Model fitting exam problem

May 20, 2013
By

Recently I have run an exam where the following question had risen many problems for students (here I give its shortened formulation). You are given the data generating process y = 10x + e, where e is error term. Fit linear regression using lm, ne...

## qdap 0.2.2 released

May 20, 2013
By

I’m very pleased to announce the release of qdap 0.2.2 This is the third installment of the qdap package available at CRAN. The qdap package automates many of the tasks associated with quantitative discourse analysis of transcripts containing discourse, including … Continue reading →

## Evaluating Columbia University’s Frontiers of Science course

May 20, 2013
By

Frontiers of Science is a course offered as part of Columbia University’s Core Curriculum. The course is controversial, with some people praising its overview of several areas of science, and others feeling that a more traditional set of introductory science courses would do the job better. Last month, the faculty in charge of the course [...]The post Evaluating Columbia University’s Frontiers of Science course appeared first on Statistical Modeling, Causal…

## What happened that the journal Psychological Science published a paper with no identifiable strengths?

May 20, 2013
By

The other day we discussed that paper on ovulation and voting (you may recall that the authors reported a scattered bunch of comparisons, significance tests, and p-values, and I recommended that they would’ve done better to simply report complete summaries of their data, so that readers could see the comparisons of interest in full context), [...]The post What happened that the journal Psychological Science published a paper with no identifiable…

## Ways to multiply in the SAS/IML language

May 20, 2013
By

For programmers who are learning the SAS/IML language, it is sometimes confusing that there are two kinds of multiplication operators, whereas in the SAS DATA step there is only scalar multiplication. This article describes the multiplication operators in the SAS/IML language and how to use them to perform common tasks [...]

## Implied alpha and minimum variance

May 20, 2013
By

Under the covers of strange bedfellows. Previously The idea of implied alpha was introduced in “Implied alpha — almost wordless”. In a comment to that post Jeff noticed that the optimal portfolio given for the example is ever so close to the minimum variance portfolio.  That is because there is a problem with the example … Continue reading →

## When Does the Kinetic Theory of Gases Fail? Examining its Postulates with Assistance from Simple Linear Regression in R

$When Does the Kinetic Theory of Gases Fail? Examining its Postulates with Assistance from Simple Linear Regression in R$

Introduction The Ideal Gas Law, , is a very simple yet useful relationship that describes the behaviours of many gases pretty well in many situations.  It is “Ideal” because it makes some assumptions about gas particles that make the math and the physics easy to work with; in fact, the simplicity that arises from these […]

## Mayo: Meanderings on the Onto-Methodology Conference

May 20, 2013
By

Writing a blog like this, a strange and often puzzling exercise[1], does offer a forum for sharing half-baked chicken-scratchings from the back of frayed pages on themes from our Onto-Meth[2] conference from two weeks ago[3]. (The previous post had notes from blogger and attendee, Gandenberger.) Several of the talks reflect a push-back against the idea that […]