Hacker News new | ask | show | jobs
by davidsrosenberg 2903 days ago
Hehe ok —- I also love Breiman’s Probability book. It’s really a standout on Ergodic theory. And Breiman et al.’s book on Trees is surprisingly rich, talking about all sorts of stuff besides trees.
2 comments

As much as I respect Brieman, I think he latched on too hard on his pet theory that all that ensembles do is reduce variance, and by doing so missed out on what boosting does.

Yeah, random forests work really well but they are layers and layers of hacks, thumb rules and intuition piled on top of the other. I cant claim with a straight face that any of them follows from solid principles.

Graycat and I have a history of discussing the differences between stats and ML here on HN. I just added a comment, up streams on the thread.

I imagine Breiman was just talking about bagging-style parallel ensembles, when he was talking about variance reduction, not boosting-style sequential ensembles. Not long before he died, he was still actively trying to figure out why AdaBoost “works”. Don’t think he claimed to really understand that. He had experimental results that disputed the “it’s just maximizing the margin” explanation.

Saw the comments above — are you from a stats or ML background, or neither?

I am more ML than stats. BTW Brieman believed the same for Boosting. Later he got a little unsure. You will find this in his writings on Boosting
Interesting -- if you've got a link, please post it.
You can take a look at his technical reports from 2001 onwards, lot of very interesting material, lot of back forth between Freund, Schapire and Brieman in those. The reports continue to be hosted on Brieman's home page.
For ergodic theory, there were a few really good lectures, and I have good notes, in a course I took from a star student of E. Cinlar.

For Breiman Probability:

(1) I liked his start, nice, simple, intuitive, on how the law of large numbers works. Of course the super nice proof is from the martingale convergence theorem, but Breiman's start is nice.

(2) His book has the nicest start on diffusions I have seen.

(3) Once in some of my work I ran into a martingale. So, then, when I wanted to review martingale theory, I went to Breiman. Nice.

(4) Since I was interested in stochastic optimal control, I was interested in measurable selection and regular conditional distributions, and I got those from Breiman -- thanks Leo!!!! Yes, IIRC, there is the relevant Sierpinski exercise in Halmos, Measure Theory and also in Loeve, Probability, but it was Breiman who gave me what I really needed.

(5) Generally Breiman is easy to read. He writes like he is trying to help the reader learn.