Bayesian News Feeds
I had never heard about Junot Díaz or The Brief Wondrous Life of Oscar Wao before A. & C. brought it to me as an hospital present. I should have, if only because it got the Pullitzer Prize (among other awards). The story is a family saga of a Dominican family, between the Dominican Republic (DR) and New Jersey where the central character Belicia Cabral de Léon emigrated. Oscar (nicknamed Wao) is her overweight son, very much into science-fiction and fantasy (from collecting cards to writing five novels) and who has indeed a brief (if definitely not wondrous) life. The Brief Wondrous Life of Oscar Wao is a complex tale of doom (fukù) and bad-luck, of ill-fated attractions and constantly wrong choices, with in the background the dark and lengthy era of the dictator Trujillo, and the still uncertain democracy in the DR. I liked very much the story, told from several characters’ perspectives, and the style as well, mixing some Spanish words with the mostly English text (which means I had to guess some sentences from my inexistent Spanish and to check for frequent words like cuero), with constant references to nerdy culture. The book time-line corresponds to the lives of Oscar and Beli and it is only towards the end that the reader finally understands how closely intertwined with Trujillo it was… (The book also includes a lot of [definitely useful] footnotes about the history of the DR from the 1930′s till the end of the dictature.) Besides the doomed (or cursed) family theme and a rather unsurprising entry into college nerdy subculture, I think The Brief Wondrous Life of Oscar Wao achieves a convincing description of (some) emigrants’ lifes, torn between two countries and somehow trapped by the “old country” culture to the point of dying from it.
Filed under: Books, Kids Tagged: Dominican Republic, emigration, fantasy, magical realism, New Jersey, Rutgers, science fiction, Trujillo
Here are a few addresses given to Le Monde Magazine travel guide by a local writer Roselyne Durand-Ruel (in the same spirit as Oxford, Miss., I mentioned a while ago!), in case you are attending ISI…:
1/ Bar Sevva’s 25e étage, Prince’s building, 10, Chater Road, Central
2/ Restaurant Tung Po Sea Food 2e étage, Cooked Food Centre, 99, Java Road, North Point. Tél. : (00-852)-28-80-52-24
3/ Centre culturel The Asia Society 9, Justice Drive, Admiralty. Tél. : (00-852)-21-03-95-11
4/ Maison de thé Lock Cha Upper Ground Floor, 290B, Queen’s Road, Central, Sheung Wan www.lockcha.com
5/ Restaurant Island Tang Shop222, The Galleria, 9, Queen’s Road, Central. Tél. : (00-852)-25-26-87-98
6/ Restaurant Tim Ho Wan 2-20 Kwong Wa Street, Mong Kok. Tél. : (00-852)23-32-28-96 [one star Michelin dim sums!]
Filed under: Books, Travel Tagged: 2013 WSC, Hong Kong, ISI, Le Monde
Following Ian Banks’ death two months ago, I decided to buy his first published novel, The Wasp Factory. After reading it, I feel sorry for not having read this book earlier, like when it appeared in 1984!, as I definitely consider The Wasp Factory a masterpiece, a standalone novel that establishes Ian Banks’s stand as a great writer (and which understandably launched Banks’ carrier).
“I killed little Esmerelda because I felt I owed it to myself and to the world in general. I had, after all, accounted for two male children and thus done womankind something of a statistical favour.”
The book tells a story that stands at the boundary of the fantastic, centred on Frank, a character that lives in a boy’s dream of weapons and secret ceremonies and auguries, alone with his dysfunctional father. It is actually never clear how much of the story is imaginary (imagined by Frank) and how much is real, from the murders of three siblings (!) to the attack of the giant rabbit to the role of the father. While Frank is apparently in his late teens, going to the pub and getting drunk, his mind seems stuck at a pre-teen stage as he worries about his catapult and carries around a bag of (animal) skulls for holding rituals and ceremonies. In many respects, The Wasp Factory reminded me of Lord of the Flies, with the same streaks of amoral cruelty and the opening on how children’s minds (could) operate when left to their own device (which is the case in the novel). Not only wasps evoke flies (!), but flies also play a major role in the novel (no more spoiler!). Verging on the Gothic, The Wasp Factory has however an additional humorous touch, from the many devices imagined by Banks to kill characters and animals to the absurd phone conversations with the equally mad brother Eric (who earlier set to burn local dogs…). Given the completely unexpected ending of the book, The Wasp Factory certainly requires a second reading to uncover all the clues that should (could?) have warned me about the conclusion. Brilliant!
Filed under: Books, Kids Tagged: fantasy, Iain Banks, rabbits, Scotland, The Wasp Factory
Filed under: Kids, Mountains, pictures, Travel Tagged: Croatia, feet, Plitvice Lakes National Park, self-portrait, Split, Venezia, Zadar
Here are my slides (or at least the current version thereof) for my talk in Hong Kong at the 2013 (59th ISI) World Statistical Congress. (I stopped embedding my slideshare links in the posts as they freeze my broswer. I wonder if anyone else experiences the same behaviour.)
This talk will feature in the History I: Jacob Bernoulli’s “Ars Conjectandi” and the emergence of probability invited paper session organised by Adam Jakubowski. While my own research connection with Bernoulli is at most tenuous, besides using the Law of Large Numbers and Bernoulli rv’s…, I [of course!] borrowed from earlier slides on our vanilla Rao-Blackwellisation paper (if only because of the Bernoulli factory connection!) and ask Mark Girolami for his Warwick slides on the Russian roulette (another Bernoulli factory connection!), before recycling my Budapest slides on ABC. The other talks in the session are by Edith Dudley Sylla on Ars Conjectandi and by Krzys Burdzy on his book The Search for Certainty. Book that I critically reviewed in Bayesian Analysis. This will be the first time I meet Krzys in person and I am looking forward to the opportunity!
Filed under: Books, Statistics, Travel, University life Tagged: 2013 WSC, ABC, ars conjectandi, Bayesian Analysis, Bernoulli factory, Hong Kong, ISI, Jacob Bernoulli, Krzysztof Burdzy, MCMC, Russian roulette, simulation, slideshare, The Search for Certainty
I have just posted on arXiv the fourth (and hopefully final) version of our paper, Relevant statistics for Bayesian model choice, written jointly with Jean-Michel Marin, Natesh Pillai, and Judith Rousseau over the past two years. As we received a very positive return from the editorial team at JRSS Series B, I flew to Montpellier today to write & resubmit a revised version of the paper. The changes are only stylistic, since we could not answer in depth a query about the apparently different speeds of convergence of the posterior probabilities under the Gaussian and Laplace distributions in Figures 3 & 4 (see paper). This was a most interesting question in that the marginal likelihoods do indeed seem to converge at different speeds. However, the only precise information we can derive from our result (Theorem 1) is when the Bayes factor is not consistent. Otherwise, we only have a lower bound on its speed of convergence (under the correct model). Getting precise speeds in this case sounds beyond our reach… (Unless I am confused with time zones, this post should come alive just after the fourth version is announced on arXiv..)
Filed under: pictures, Statistics, Travel, University life Tagged: ABC, asymptotics, Bayesian model choice, convergence assessment, JRSSB, leaves, marginal likelihood, Montpellier, pergola, truck
While I got an advance reader’s copy of numbersense, Kaiser Fung’s latest book, sent to me by the publisher McGraw-Hill, I did not managed to write a review until the book had been out for two months. The title of the book is clear enough about the purpose of the author, but the subtitle “How to use Big Data to your advantage” stresses it even further. And includes the sesame “Big Data”, much more likely to appeal to the general reader than “statistics”…!
“I wouldn’t blame you if you are ready to burn this book, and vow never to talk to the lying statisticians ever again.” (p.4)
So why did it take me such a long while to compose this review?! Besides the break induced by The Accident (I took the book to the hospital but ended up reviewing R for Dummies instead!), I figure I got rather taken aback by the style and intended audience of numbersense, given my earlier reading and enjoying Numbers rule your world. While the book remains of interest for statisticians (and other CHANCE readers!), providing examples to use in the classroom, the statistical connection is all but visible to the casual reader who may well conclude that numbersense is a form of numerical common sense of about fighting innumeracy, rather than modelling uncertainty thru statistical models.
“In analyzing data, there is no way to avoid having theoretical assumptions (…) The world has never run out of theoreticians; in the era of Big Data, the bar of evidence is reset lower, making it tougher to tell right from wrong.” (p.11)
Overall, the intended audience of numbersense seems even further away from statistically savy readers than Numbers rule your world. The book is divided into four sections: social data (Chap. 1 & 2), marketing data (Chap. 3-5), economic data (Chap. 6 & 7), and sport data (Chap. 8). Plus a prologue on the Simpson paradox (in marketing), involving Howard Wainer whose Uneducated Guesses: Using Evidence to Uncover Misguided Education Policies I reviewed a while ago. The first (more marketing than social) chapter is about doctoring admission policies against GPA and LSAT scores (whatever that means!) to improve the ranking of a school. This does not sound such a major numerical issue (once the trick is uncovered) and the chapter meanders too much to my taste. The second chapter goes back to Quetelet‘s impossible average man. Asking the reader to question the role of indices in definitions (like obesity). And mentioning the “significant result” bias in medical journals in passing. As well as causality. As in the previous chapter, I finished it waiting for a conclusion that never came. Chapters 3 and 4 focus on Groupon, Without much of a statistical model (except maybe a second-order Simpson paradox?). Chapter 6 is about how companies like Amazon target their suggestions to customers. Not elaborating on the logit or whatever model is behind, though, and drifting aside on the breach of data secrecy by most of “those” companies. The economics chapters are more to my liking, presumably because they are more standard, covering the subtleties of unemployment and inflation (official) statistics. They fall into what I call the Gini index branch of statistics. At last, the sport chapter is about fantasy football (FF) and not about Moneyball (even though it has links, obviously). I did not go father than a quick perusal at the chapter as I did not understand (most of) the point of the chapter (or of playing FF). For instance, the conclusion seemed quite distanced from the actual story…
“today’s computers do not understand languages. All they do is match text: they can tell me whether the words “empirical Bayes model” are found on a specific Web page.” (p. 209)
The epilogue is of a different nature as it describes two examples of the tasks undertaken by Kaiser Fung as a data analyst. A nasty data transfer. And a manual classification of some Google queries. This may be the part of numbersense that I enjoyed the most. Again, let me stress I have no scientific complaint about the book: it just sounds too low-tech’ for my taste. And I find it is not helping readers to go beyond the first level of scepticism about raw and processed data. Because they are not data-analysts.
Filed under: Books, Statistics Tagged: big data, data-analyst, educational tests, fantasy football, Kaiser Fung, marketing, popular science
Filed under: Wines Tagged: carigan, grenache, Languedoc, Larzac, Les Vieilles Vignes, Saint-Privat, Syrah
The great discussion Tony O’Hagan had with Dennis Lindley last March for the Bayes 250 meeting at the RSS is now available on line.
Since this is still close to Dennis’s birthday, I take the opportunity to wish him the best for his 90th birthday.
Filed under: Statistics, University life Tagged: Bayes 250, Dennis Lindley, RSS, Tony O'Hagan
Thanks to Nicolas Chopin, I took Wool to Croatia as part of my summer read survival package! This book actually started as a short story, then as short stories, written directly for Kindle by the author Hugh Howey, and the printed book is “only” a post-processing of those short stories. Two more books are planned in the series. Look out for spoilers in the following!
“And that’s when Juliette realised what she must do. A project to put the wool back from everyone’s eyes, a favor to the next fool who slipped up or dared to hope aloud. And it would be easy. ” Wool
The plot of Wool is rather standard: a group of people forced to live in autarcy in an underground shelter because of a contaminated outside world. The shelter (called the silo) is highly functional and unravels to be designed against the outside contamination, which leads some inhabitants of the silo to question the reason for being stuck there for generations, with no memory of the catastrophic events that led to this collective internment. Some among those wonder hard enough to challenge the authorities of the silo and, while most of those are exiled outside to a quick and painful death, one manages to escape and eventually uncovers the truth. Or part of the truth.
While I generally like those post-apocalyptic and closed universes where the inhabitants have to recycle and reinvent everything from the available material, a modern version of the Robinson (Crusoe vs. Swiss family) novels, I am a wee disappointed with this aspect of Wool, because the silo was supposedly created towards this goal of hosting a group of people for centuries and thus should have the proper amenities, without technicians loosing track of things like radio transmission in so few generations. (Of course, there is this special drug inoculated to [almost] all inhabitants of the silo that is erasing past memories but…) The power struggle in Wool also sounds weak in that the domination of the IT unit should have been more obvious from the start. Reading the prologue to the second volume, Shift, I wonder how well it connects with the first one, if it may be trying too hard to explain the past and how the silo was designed with the catastrophe in mind. Overall, it reads more like young adult science fiction than a major book. But it was nonetheless enjoyable for a summer read!
Filed under: Books, Kids Tagged: dystopia, Hugh Howey, Robinsons, science fiction, wool