## philosophy at the 2015 Baccalauréat

Posted in Books, Kids with tags , , , , , , , , , , on June 18, 2015 by xi'an

[Here is the pre-Bayesian quote from Hume that students had to analyse this year for the Baccalauréat:]

The maxim, by which we commonly conduct ourselves in our reasonings, is, that the objects, of which we have no experience, resembles those, of which we have; that what we have found to be most usual is always most probable; and that where there is an opposition of arguments, we ought to give the preference to such as are founded on the greatest number of past observations. But though, in proceeding by this rule, we readily reject any fact which is unusual and incredible in an ordinary degree; yet in advancing farther, the mind observes not always the same rule; but when anything is affirmed utterly absurd and miraculous, it rather the more readily admits of such a fact, upon account of that very circumstance, which ought to destroy all its authority. The passion of surprise and wonder, arising from miracles, being an agreeable emotion, gives a sensible tendency towards the belief of those events, from which it is derived.” David Hume, An Enquiry Concerning Human Understanding,

## Bayes at the Bac’ [again]

Posted in Kids, Statistics with tags , , , , , , , , on June 19, 2014 by xi'an

When my son took the mathematics exam of the baccalauréat a few years ago, the probability problem was a straightforward application of Bayes’ theorem.  (Problem which was later cancelled due to a minor leak…) Surprise, surprise, Bayes is back this year for my daughter’s exam. Once again, the topic is a pharmaceutical lab with a test, test with different positive rates on two populations (healthy vs. sick), and the very basic question is to derive the probability that a person is sick given the test is positive. Then a (predictable) application of the CLT-based confidence interval on a binomial proportion. And the derivation of a normal confidence interval, once again compounded by  a CLT-based confidence interval on a binomial proportion… Fairly straightforward with no combinatoric difficulty.

The other problems were on (a) a sequence defined by the integral

$\int_0^1 (x+e^{-nx})\text{d}x$

(b) solving the equation

$z^4+4z^2+16=0$

in the complex plane and (c) Cartesian 2-D and 3-D geometry, again avoiding abstruse geometric questions… A rather conventional exam from my biased perspective.

## detachment

Posted in Books, Kids with tags , , , on May 19, 2013 by xi'an

One of the movies I watched during my hospitalisation is detachment, by Tony Kaye, with Adrian Brody as the lead actor. My daughter brought it to me as she remembered I was interested in it. detachment is a strong and highly original movie about the U.S. school system and the complete lack of prospects for the students in deprived suburbs. I have seen several movies of that kind in the past, some of them rather good and keeping away from the fairy tale that an exceptional teacher is enough to rescue a class cohort or even a single student from a bleak future. This one is however the most pessimistic of all, with no happy ending of any sort (except for the last minute that should have been cut). The plot is not flawless, e.g. the main teacher redemption of the young prostitute being just too unrealistic, but the burnout of the teachers, the newspeak preaching of the administration, the nihilism of the high school students, the bullying of unusual students, and the complete absolute absence of the parents (unless I am confused we only see one [screaming] mother once, no parent shows up at parents’ night and the bullying father is only a voice…) make up for those flaws. Adrian Brody is delivering a superb performance in a great movie, sadly about a terrible issue with our educational system(s)…