Blog Archives

How to map geographically-detailed survey responses?

January 17, 2012
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David Sparks writes: I am experimenting with the mapping/visualization of survey response data, with a particular focus on using transparency to convey uncertainty. See some examples here. Do you think the examples are successful at communicating both local values of the variable of interest, as well as the lack of information in certain places? Also, The post How...

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R-squared for multilevel models

January 15, 2012
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Fred Schiff writes: I’m writing to you to ask about the “R-squared” approximation procedure you suggest in your 2004 book with Dr. Hill. I’m a media sociologist at the University of Houston. I’ve been using HLM3 for about two years. Briefly about my data. It’s a content analysis of The post R-squared...

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Using factor analysis or principal components analysis or measurement-error models for biological measurements in archaeology?

December 31, 2011
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Greg Campbell writes: I am a Canadian archaeologist (BSc in Chemistry) researching the past human use of European Atlantic shellfish. After two decades of practice I am finally getting a MA in archaeology at Reading. I am seeing if the habitat or size of harvested mussels (Mytilus edulis) can be reconstructed from measurements of the The post Using...

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Ripley on model selection, and some links on exploratory model analysis

December 17, 2011
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This is really fun. I love how Ripley thinks, with just about every concept considered in broad generality while being connected to real-data examples. He’s a great statistical storyteller as well. . . . and Wickham on exploratory model analysis I came across Ripley’s slides in a reference from Hadley Wickham’s article on exploratory model The post Ripley...

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CrossValidated: A place to post your statistics questions

December 16, 2011
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CrossValidated:  A place to post your statistics questions

Seth Rogers writes: I am a member of an online community of statisticians where I burn a great deal of time (and a recovering cog sci researcher). Our community website is a peer-reviewed Q and A spanning stats topics ranging from applications to mathematical theory. Our online community consists of mostly university faculty, grad The post CrossValidated:...

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Permanently Setting the CRAN repository

November 29, 2011
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Setting the CRAN repository so that it does not ask every time you try to install a package  is something that I think few people bother to do, but it is so simple and can save a fair bit of frustration when working.  This is accomplished through a setting in one of the Rprofile files.  There

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World record running times vs. distance

November 15, 2011
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World record running times vs. distance

Julyan Arbel plots world record running times vs. distance (on the log-log scale): The line has a slope of 1.1. I think it would be clearer to plot speed vs. distance—then you’d get a slope of -0.1, and the numbers would be more directly interpretable. Indeed, this paper by Sandra Savaglio and Vincenzo Carbone (referred The post World...

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Wickham R short course

November 14, 2011
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Hadley writes: I am going to be teaching an R development master class in New York City on Dec 12-13. The basic idea of the class is to help you write better code, focused on the mantra of “do not repeat yourself”. In day one you will learn powerful new tools of abstraction, allowing The post Wickham...

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Web-friendly visualizations in R

October 19, 2011
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Aleks points me to this new tool from Wojciech Gryc. Right now I save my graphs as pdfs or pngs and then upload them to put them on the web. I expect I’ll still be doing this for awhile—I like having full control of what my graphs look like—but Gryc’s default plots might be useful The post Web-friendly...

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Why it doesn’t make sense to chew people out for not reading the help page

October 12, 2011
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Karl Broman writes: Barry Rowlingson gave an interesting talk at UseR 2011, “Why R-help must die!” He suggested the Q-and-A type sites Stack Overflow (on programming) and Cross Validated (on statistics), both part of Stack Exchange. I haven’t used R-help recently but I do occasionally send people there. Just to see what was going on The post Why...

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