Archive for jaguars

where K. works

Posted in Books, Mountains, pictures, Statistics, Travel, University life with tags , , , , , , , , on December 2, 2019 by xi'an

Pitman medal for Kerrie Mengersen

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , on December 20, 2016 by xi'an

6831250-3x2-700x467My friend and co-author of many years, Kerrie Mengersen, just received the 2016 Pitman Medal, which is the prize of the Statistical Society of Australia. Congratulations to Kerrie for a well-deserved reward of her massive contributions to Australian, Bayesian, computational, modelling statistics, and to data science as a whole. (In case you wonder about the picture above, she has not yet lost the medal, but is instead looking for jaguars in the Amazon.)

This medal is named after EJG Pitman, Australian probabilist and statistician, whose name is attached to an estimator, a lemma, a measure of efficiency, a test, and a measure of comparison between estimators. His estimator is the best equivariant (or invariant) estimator, which can be expressed as a Bayes estimator under the relevant right Haar measure, despite having no Bayesian motivation to start with. His lemma is the Pitman-Koopman-Darmois lemma, which states that outside exponential families, sufficient is essentially useless (except for exotic distributions like the Uniform distributions). Darmois published the result first in 1935, but in French in the Comptes Rendus de l’Académie des Sciences. And the measure of comparison is Pitman nearness or closeness, on which I wrote a paper with my friends Gene Hwang and Bill Strawderman, paper that we thought was the final paper on the measure as it was pointing out several majors deficiencies with this concept. But the literature continued to grow after that..!

statistics with jaguars

Posted in pictures, Statistics, Travel, University life with tags , , , on April 8, 2016 by xi'an
Following a field trip to Péru of my friend Kerrie Mengersen and other researchers from QUT, to study jaguar population, The Australian ran a story about this most exotic expedition. (Although Kerrie is familiar with exotic topics, since she also worked on cheetahs in Africa and orang-utans in Indonesia.) While the newspaper does not get into the details of the mathematical model used to describe the jaguar population, it turns quite lyrical about the expedition itself and the interactions with the local human populations. In the end it does not sound that terrible that the group could not see any jaguar, despite evidence of a strong presence in the area, as everyone came back unscathed!