Le bayésianisme aujourd’hui

A few years ago, I was asked by Isabelle Drouet to contribute a chapter to a multi-disciplinary book on the Bayesian paradigm, book that is now soon to appear. In French. It has this rather ugly title of Bayesianism today. Not that I had hear of Bayesianism or bayésianime previously. There are chapters on the Bayesian notion(s) of probability, game theory, statistics, on applications, and on the (potentially) Bayesian structure of human intelligence. Most of it is thus outside statistics, but I will certainly read through it when I receive my copy.

travel madness

Certainly the 43 hours trip to San Francisco on Friday and Saturday was one of the worst travels I ever experienced as we were delayed, disembarked and left waiting in queues for most of two days. The August vacation peak weekend “coincided” with an Air France strike action by flight attendants and a correlated lack of ground personal in the airport. Rather than cancelling flights, Air France chose to downsize the number of passengers on board depending on the available flight attendants on that flight, which is presumably less expensive for the company. And so nice for the disembarked passengers, frequent fliers included. This was the Friday morning flight. We got rebooked to the Friday afternoon flight. Meaning six hours in the Air France lounge. After one hour delay, the afternoon flight rode for about 100 meters when leaking fuel was detected, apparently due to overfull tanks. Getting this sorted took around three hours, after which the captain told us that labour regulations prevented him and the crew to fly to San Francisco as it would be too long a working day. The whole plane was disembarked, which took another hour, to a transit area with hundred of people and no airline representative. Eventually someone from Air France appeared and started talking to people around rather than making a global announcement. Herding us back outside the restricted area with vague indications to get to another part of the terminal for rerouting. After more delays and chaos we ended up in another queue for hotel vouchers as the only choice was to wait for a specially chartered plane at noon the next day, our baggage being sealed and inaccessible. It took hours to get those vouchers and reach the airport hotel by midnight, before rushing back the next morn to another vaguely specified rendez-vous. This worked out more smoothly, except for another three hours delay waiting for enough flight attendants to show up.  This ruined our chances to get there in time to recover material for the race. Fortunately, our son managed to board an earlier plane [if last on board!] and grab it for us.

The worst thing about this [first world problem!] trip was not the strike or the cancellations, but the complete disorganisation of the management of the issues, with the passengers being herded from one place to another with contradictory items of information by clueless airline representatives. I figure this may be a consequence of the strike as well, the airport desks being poorly staffed for a major vacation weekend.  [Again, first world problem, no one was hurt and we just lost one vacation day. Plus the opportunity to write half a dozen posts.]

Bastille day

 

After seeing the above poster in the Paris métro over the past weeks, announcing the opening of the Bastille Day movie the day before Bastille Day, on July 13, I wanted to write an entry about the absurdity of the title for a French audience, since the 14th of July is not called Bastille Day in France but either la fête nationale or simply le 14 juillet…

But the senseless massacre of a crowd watching the fireworks in Nice by a madman on the night of July 14 makes both the comment and the movie (which has been taken off French cinemas) irrelevant. In memory of all victims and support for all injured and suffering.

radishes

This year, a new stand at the farmers’ market offers local and unusual varieties of fruits and vegetables, including radishes of at least five different colours. When I bought a bunch yesterday morning, the seller gave me two additional bunches, which means I will be eating radishes the whole week (or until they get too peppery!).

(mis)selection at French universities

There was an most relevant article in the weekend edition of Le Monde about the absurd posture of French laws, governments and universities about prohibiting any selection at the entrance to university. Under the current regulation, anyone with the baccalauréat degree can apply to any first year program and expect to be accepted. Since this is impossible, universities have to discriminate based on the current address and, if there still are too many applicants, resort to random sampling. To avoid selecting based on high school records or even the final grades at the State level baccalauréat. Or the same universities have to invent some local degrees that are not recognised as national (State) degrees. This is more than absurd, obviously, as it drives most of the best students away from the university system into private schools or abroad. (Paris-Dauphine chose a few years ago to opt out from being a national university, in order to select its students and is thus private in this respect if public in its funding.)

One extreme [and personal] example of this Kafkaian (dis)organisation is provided by medical studies. Anyone with a baccalauréat with any major (science, humanities, carpentry, …) can on principle enter a medical school! Obviously, there must be some selection before too many patients die or too many doctors graduate and the way it operates is as follows: a huge number of students enter the first year of medical studies where they follow mass teaching, with courses mostly on video and tutoring from second year students. They take two one-day exams in December and May with only multiple answer questions. And about 10% of those students are accepted in second year… Among the 90% who fail, about 40% are allowed to try again. Once. [Our daughter thus spent two years of intense bachotage to enter the second year. Congrats to her for her dedication and success!] In the end, French doctors are certainly not worse than others, but this remains a waste of time, energy and money for a huge number of people, with no other argument than an ideological call to égalité. Which translates in practice into a huge inequality between students who can afford private tuition and massive family logistic support [as we found out!] and those who cannot. Furthermore, some universities are bursting at the seams with the number of first year medical students, in constant augmentation despite the 10% success rate. And are thus considering introducing random sampling as well! Using the (costly) baccalauréat to restrict the number of accepted first years students would seem reasonable and rational, as would a more directive orientation of high school students as advocated by Le Monde. An unlikely move, given the potential political impact of the measure.

snapshot from Amiens [#2]

church comics

During Easter break, a last minute airbnb reservation led us to visit the cathedral of Amiens (in North-East France, near the Battle of the Somme front) with its (42m) soaring ceilings and its immense nave. The central choir is surrounded by an ambulatory with niches of intricate polychrome sculptures of stories of saints that look like 3D-comics. Similar to those Jim and I already spotted in the cathedral of Chartres! In Amiens, there were several of them, including a vivid representation of the life and afterlife of Saint Fermin. (With an exhumation of his body (below) worth the visit by itself: the priest using the spade is so much into it!) As well as a life of John the Baptist, whose head was supposed to have ended up in the cathedral…