The AstroStat Slog

Grand statistical challenges seem to be all the rage nowadays. Following on the heels of the Banff Challenge (which dealt with figuring out how to set the bounds for the signal intensity that would result from the Higgs boson) comes the GREAT08 Challenge (arxiv/0802.1214) to deal with one of the major issues in observational Cosmology, the effect of dark matter. As Douglas Applegate puts it: Continue reading ‘The GREAT08 Challenge’ »

It seems like I omit papers deserving attentions from time to time. If you find one, please leave a message. Even better if a summary can be left for a separate posting. Continue reading ‘[ArXiv] 3rd week, Feb. 2008’ »

First posting regarding astrostatistics related job opportunities. Tom Loredo kindly informed us. Hopefully there are more to come.
Continue reading ‘Scientific Programmer for the Kepler Mission’ »

I was reading [1]. I must say that I do not know Bayesian methods to cope with model misspecification, tests with an unknown true model, or tests for non-nested hypotheses except Bayes factor (concerns a lot how to choose priors). Nonetheless, the zeal among economists to test non-nested models might assist astronomers to move forward beyond testing nested hypotheses with F statistic. Continue reading ‘Non-nested hypothesis tests’ »

From page 103 of Bayesian Model Selection and Model Averaging by L. Wasserman (2000) Journal of Mathematical Psychology, 44, pp.92-107 Continue reading ‘[Quote] When all the models are wrong’ »

Another week went by with astro-ph papers of statistical flavors. Continue reading ‘[ArXiv] 2nd week, Feb. 2008’ »

Last week, I was at Tufts colloquium and happened to have a conversation with a computer scientist about density based clustering. I understood density as probabilistic density and was recollecting a paper by Fraley and Raftery (Model-Based Clustering, Discriminant Analysis, and Density Estimation, JASA, 2002, 97, p.458) and other similar papers I saw in engineering journals like IEEE transactions. For a few moments, I felt uncomfortable and she explained that density meant “how dense observations are.” Density based clustering was meant to be distance based clustering, like k-means, minimum spanning tree, most likely nonparametric approaches. Continue reading ‘language barrier’ »

Review papers on Bayesian hierarchical modeling and LAR (least angle regression) appeared in this week’s stat arXiv and in addition to interesting astro-ph papers.

A review paper on LASSO and LAR: [stat.ME:0801.0964] T. Hesterberg et.al.
   Least Angle and L₁ Regression: A Review
Model checking for Bayesian hierarchical modeling: [stat.ME:0802.0743] M. J. Bayarri, M. E. Castellanos
   Bayesian Checking of the Second Levels of Hierarchical Models
Continue reading ‘[ArXiv] 1st week, Feb. 2008’ »

When: June 9-14, 2008
Where: Penn State
Registration deadline: Apr. 18, 2008 [Previous years, it ended weeks before.]
The summer school website: http://astrostatistics.psu.edu/su08/. Continue reading ‘AstroStatistics Summer School at Penn State ’08’ »

Some statistics papers were listed at the top, of which topics would interest some slog subscribers.
Continue reading ‘[ArXiv] 5th week, Jan. 2008’ »

This is an edited email copy of Colloquium Announcement from Tufts University, MA. A must go for those live in Medford and Somerville, where Tufts Univ. is located and its vicinity.

Subject : Special Joint CS and Physics Colloquium
Title : How Astronomers, Computer Scientists and Statisticians are working together to tackle hard problems in astronomy
Speaker: Pavlos Protopapas
Date : Thursday February 7
Time : 3:15 pm
Place : Nelson Auditorium, Anderson Hall (Click for the map, 200 College Ave, Medford, MA, I think)
Abstract: Continue reading ‘working together to tackle hard problems in astronomy’ »