Yet another puzzle which first part does not require R programming, even though it is a programming question in essence: Given five real numbers x1,…,x5, what is the minimal number of pairwise comparisons needed to rank them? Given 33 real numbers, what is the minimal number of pairwise comparisons required to find the three largest ones? […]
re:log [opendatacity.de] by German data designers OpenDataCity reveals the movements of about 6,700 different electronic devices during re:publica 2013, a prestigious European conference on the topic of Digital Society. A dynamic map of the conferenc...
Map Stack [stamen.com] by Stamen Design aims to make it radically simpler for lay people to design completely unique, personalized maps. The online visual map design service provides easy access to the color, opacity and brightness of any map backgro...
This post is by Phil. A little over three years ago I wrote a post about exercise and weight loss in which I described losing a fair amount of weight due to (I believe) an exercise regime, with no effort to change my diet; this contradicted the prediction of studies that had recently been released. [...]The post There are no…
After months of work (although to be fair, we haven't worked 100% full time on this), Andrea and I are nearly ready to publish the next release of BCEA. Andrea has done a brilliant job and is responsible for most of the good new features (NB: see ...
Postdoctoral position in statistical modeling of social networks A full-time postdoctoral position is available beginning Fall 2014 in the research group of Tian Zheng and Andrew Gelman working on statistical analysis and modeling of social network data, in close cooperation with our experimental collaborators. Four key papers of this project so far are: http://www.stat.columbia.edu/~gelman/research/published/overdisp_final.pdf http://nersp.osg.ufl.edu/~ufruss/documents/mccormick_salganik_zheng10.pdf [...]The post Job opening! Come…
Andrew Sullivan (link) has a few questions about a new Pew survey focusing on the LGBT subpopulation. He wonders, for instance, about the high proportion of self-identified bisexuals in this poll. What interests a statistician here is the fact that the poll deals with sensitive matters, which typically present a challenge in terms of survey response, and nonresponse bias. The…
The Google Charts Tools provide two kinds of heat map charts for geographical data, the Flash based Geomap and the HTML5/SVG based Geochart. I prefer the Geochart as it doesn't require Flash, but so far there have been two shortcomings with it: I...
This test is the first attempt to seriously assess the ability of individuals to survive a zombie apocalypse. This test is administered using the R powered open-source testing platform Concerto developed at the University of Cambridge. The t...
I just updated my short review on Bayesian computational tools I first wrote in April for the Annual Review of Statistics and Its Applications. The coverage is quite restricted, as I took advantage of two phantom papers I had started a while ago, one with Jean-Michel Marin, on hierarchical Bayes methods and on ABC. (As […]
Matt Selove writes: My question is about Bayesian analysis of the linear regression model. It seems to me that in some cases this approach throws out useful information. As an example, imagine you have two basketball players randomly drawn from the pool of NBA players (which provides the prior). You’d like to estimate how many [...]The post Weak identification provides…
David Shor sends along a job announcement for Civis Analytics, which he describes as “basically Obama’s Analytics team reconstituted as a company”: Data Scientist Position Overview Data Scientists are responsible for providing the fundamental data science that powers our work – including predictive analytics, data mining, experimental design and ad-hoc statistical analysis. As a Data [...]The post Job opening at…
Today, we review one of the basic principles Ed Tufte very effectively advocated in his famous book: use gridlines and data labels only if absolutely necessary. The enemy is redundancy. Here is a chart that appeared in the New York...
A regular reader noticed my post on initializing vectors by using repetition factors and asked whether that technique would be useful to expand data that are given in value-frequency pairs. The short answer is "no." Repetition factors are useful for defining (static) matrix literals. However, if you want to expand [...]
Introduction Recently, I began a series on exploratory data analysis (EDA), and I have written about descriptive statistics, box plots, and kernel density plots so far. As previously mentioned in my post on box plots, there is a way to combine box plots and kernel density plots. This combination results in violin plots, and I […]
In 1973, Anscombe presented four data sets that have become a classic illustration for the importance of graphing the data, not merely relying on summary statistics. The four data sets are now known as "Anscombe's quartet." Here I present a Bayesian ap...
I’m kidding about poets. But lots of people need to understand the three basic areas of statistics, Chance, Data and Evidence. Recently Tony Greenfield, an esteemed applied statistician, (with his roots in Operations Research) posted the following request on a … Continue reading →
Getting Expected Shortfall given the standard deviation or Value at Risk. Previously There have been a few posts about Value at Risk and Expected Shortfall. Properties of the stable distribution were discussed. Scaling One way of thinking of Expected Shortfall is that it is just some number times the standard deviation, or some other number … Continue reading →
Datapalooza! I'm wondering where my invite is? I do health data stuff, pick me, pick me! Actually it does sound like a pretty good idea - in general giving a bunch of smart people access to interesting data and real … Continue reading →
The other day, a friend told me that when he saw me blogging on Noam Chomsky, he was surprised not to see any mention of disgraced primatologist Marc Hauser. I was like, whaaaaaa? I had no idea these two had any connection. In fact, though, they wrote papers together. This made me wonder what Chomsky [...]The post Evilicious: Why We…
Two weeks ago I described car data, among which weight distribution of cars in Netherlands. At that time it was purely plots. In the mean time I decided I wanted to model trends. As a first step of that, I decided to fit distributions for these da...
Open Data Census The Open Knowledge Foundation OKFN publishes first results of its Open Data Census, just before the G8 …Continue reading »
Steve Miller writes: Much of what I do is cross-national analyses of survey data (largely World Values Survey). . . . My big question pertains to (what I would call) exploratory analysis of multilevel data, especially when the group-level predictors are of theoretical importance. A lot of what I do involves analyzing cross-national survey items [...]The post Exploratory multilevel analysis…
