Data analysis recipes: Fitting a model to data: We go through the many considerations involved in fitting a model to data, using as an example the fit of a straight line to a set of points in a two-dimensional plane. Standard weighted least-squares fitting is only appropriate when there is a dimension along which the [...]
Josef Fruehwald writes: In the past few years, the empirical foundations of the social sciences, especially Psychology, have been coming under increased scrutiny and criticism. For example, there was the New Yorker piece from 2010 called “The Truth Wears Off” about the “decline effect,” or how the effect size of a phenomenon appears to decrease [...]
I think cross-validation is a good way to estimate a model’s forecasting error but I don’t think it’s always such a great tool for comparing models. I mean, sure, if the differences are dramatic, ok. But you can easily have a few candidate models, and one model makes a lot more sense than the others [...]
Cosma Shalizi and Larry Wasserman discuss some papers from a conference on Ockham’s Razor. I don’t have anything new to add on this so let me link to past blog entries on the topic and repost the following from 2004: A lot has been written in statistics about “parsimony”—that is, the desire to explain phenomena [...]
Larry Wasserman, a leading theoretical statistician and generally thoughtful guy, has started a blog on . . . theoretical statistics! Good stuff, and readers of this blog should enjoy the different perspective that Larry offers. Here are some earlier references to Larry on this blog, and here’s a discussion that gives a sense of our [...]
I know next to nothing about golf. My mini-golf scores typically approach the maximum of 7 per hole, and I’ve never actually played macro-golf. I did publish a paper on golf once (A Probability Model for Golf Putting, with Deb Nolan), but it’s not so rare for people to publish papers on topics they know [...]
Aki writes: Here’s my version of the birthday frequency graph. I used Gaussian process with two slowly varying components and periodic component with decay, so that periodic form can change in time. I used Student’s t-distribution as observation model to allow exceptional dates to be outliers. I guess that periodic component due to week effect [...]
Jay Livingston points to an excellent rant from Peter Moskos, trashing a study about “food deserts” (which I kept reading as “food desserts”) in inner-city neighborhoods. Here’s Moskos: From the Times: There is no relationship between the type of food being sold in a neighborhood and obesity among its children and adolescents. Within a couple [...]
I read this front-page New York Times article and was immediately suspicious. Here’s the story (from reporter Gina Kolata): Could exercise actually be bad for some healthy people? A well-known group of researchers, including one who helped write the scientific paper justifying national guidelines that promote exercise for all, say the answer may be a [...]
Jay Jones writes: I recently came across your paper on average predictive comparisons (Gelman and Pardoe, 2007) and can see many applications for this in my work (I’m an applied statistician working for Weyerhaeuser Company at our R&D center near Seattle). At the moment, I am using APC’s to help describe the results of a [...]
