Comment author: tadrinth 04 April 2012 02:08:28AM 22 points [-]

I'm not sure if anyone has commented on this, but I just noticed it while rereading the Self-Actualization chapters:

Hermione went to tremendous lengths to be her own person rather than just something of Harry's, including becoming a general and fighting bullies. Now she has sworn herself into Harry's service and house forever. That is really sad.

Comment author: smk 30 March 2012 05:24:41AM 3 points [-]

In Ch 45, Harry thinks:

I comprehend your nature, you symbolize Death, through some law of magic you are a shadow that Death casts into the world.

If this is true, it's possible that as long as death exists (for wizards, anyway), it will continue to cast its shadows, and so the dementors can never be all destroyed. Maybe they'll just respawn or something. In fact, maybe when Harry destroyed that one in Ch 45, a dementor respawned back at Azkaban without anyone noticing. Do the guards keep a count of dementors?

Comment author: tadrinth 31 March 2012 09:19:26PM *  0 points [-]

The dementors serve at least three purposes in Azkaban: they drain the magic from prisoners to render them helpless, they notify the guards when prisoners escape, and they chase down and incapacitate escaped prisoners and intruders. If Harry destroys 90% of the dementors, there probably won't be enough left for the first or third purposes. That would make Azkaban much less secure, and the perception of Azkaban's security would go down if there are hardly any dementors since the dementors are what make it infallible. Even just demonstrating that Dementors CAN be destroyed would probably force them to completely remake Azkaban to not depend on the dementors.

Comment author: buybuydandavis 28 March 2012 07:08:39PM 4 points [-]

One thing I noticed about Harry's language - increasing talk in computer terms. PC, SYSTEM ERROR, Internal Consistency Checker.

His Dark Side is tremendously efficient at information recall and causal inference. Interesting that Quirrell remarked on the value of memory recall to a wizard. I've wondered if the Dark Side was just an interface to a computing system, but it's clear that's not all that it is.

It seems like the Dark Side is two things, an efficient computation engine, and the dark emotions related to Death: the terror and hatred. Why are those linked? Why does a computation and recall engine have to be linked to emotions at all, and if it's going to be emotions, why not positive Mr. Glowy Person feelings?

Comment author: tadrinth 29 March 2012 08:42:56PM 0 points [-]

The dark side is presumably the result of the botched Horcrux creation ritual and is in some way an aspect of Voldermort's mind or soul. An AI might have different modules for emotions and computation, but a human mind is not so cleanly separated.

Comment author: wedrifid 29 March 2012 01:33:42PM 3 points [-]

The Dementor's goal was to not die. You don't generally accomplish that by antagonizing the one guy who can kill you.

Unless they already plan to kill you, in which case antagonizing them can potentially reduce their threat.

Comment author: tadrinth 29 March 2012 08:36:06PM 3 points [-]

Ah, but Harry doesn't intend to kill Dementors in particular, he aims to eradicate death itself (destroying them indirectly) and he is NOT confident that he will accomplish that in his lifetime. A Dementor that pisses off Harry dies immediately, while a Dementor that doesn't will only die if Harry lives long enough to succeed.

Comment author: Alicorn 25 March 2012 02:15:12AM 3 points [-]

I did send in an application to the Center for Modern Rationality but I haven't heard back

Please email me (elcenia@gmail.com) and tell me which types of work you wanted. There has been a spreadsheet-tracking issue, and I'm not sure who I have and haven't reached yet. (I'm considering just mass-mailing everybody on the list with "if you haven't heard from me before, please let me know and I can give you sample work". Thoughts on whether this would be more obnoxious than helpful?)

Comment author: tadrinth 25 March 2012 05:56:27AM *  3 points [-]

Email sent!

I think people would appreciate knowing that they might still have a shot even if they haven't heard anything. You could maybe ask Eliezer to put a note that you're still wading through applications in his next HPMOR author's note. =P Otherwise, I think a mass email would not be too annoying to those who have already heard from you and very much appreciated by those who haven't.

Comment author: Manfred 25 March 2012 02:47:59AM *  1 point [-]

I haven't read Bolstad, but I think that grokking the first 3-ish chapters of Jaynes seems like a reasonable requirement for being able to explain why probability looks the way it does. The actual "methods" chapters after that aren't really useful/necessart for undergrads, except for the simple stuff like "given some data, what's the likelihood ratio for your hypothesis? How about the null hypothesis?" You could always jump into teaching without re-reading that, but iunno.

Comment author: tadrinth 25 March 2012 05:48:30AM *  1 point [-]

Yeah, the early stuff in Jaynes is pretty comprehensible (the ideas are clear if not all the proofs). Intro stats classes tend to be very light on the proofs, though. They're very much "here's probability", not "here's why probability". I'll definitely reread Jaynes again before teaching, but I want to finish Bolstad and work through some of the problems before that.

Comment author: othercriteria 25 March 2012 01:17:47AM 3 points [-]

All of the really smart professors I know personally who have an opinion on the topic are Bayesians, Less Wrong as a community prefers Bayesianism, and I prefer it.

Is this how you would respond to a hypothetical student of yours asking why you're not a frequentist? Sorry for the snark, but you are considering a career choice where you would be a voice for Bayesianism to your students and fellow faculty. I think you owe it to those who want Bayesian methods to be treated seriously to acquaint yourself with de Finetti's theorem, Cox's theorem, the frequentist consistency (or lack thereof) of Bayesian procedures, etc.

Also, I'm pretty sure this is not the best way you could get paid to raise the sanity or rationality waterline, given your background. Think about the marginal effect of taking such a job. Best case, you'll either teach a Bayesian stats courses that otherwise wouldn't be taught due to lack of faculty or replace someone who would otherwise teach it (that person will probably be have better or equal academic credentials and might be less enthusiastic about Bayesianism). But students who would choose to take a Bayesian stats course will probably do fine anyways. Teaching intro (frequentist) stats well or doing private tutoring for students stuck in bad intro stats courses will be more likely to make a difference.

Comment author: tadrinth 25 March 2012 05:40:38AM *  3 points [-]

I do need to read up on those; Jaynes talks about the implications of Cox's theorem but doesn't go into it directly, so I'm only vaguely familiar. Thank you for the reading suggestions. I did plan to talk about those issues in the introduction of the course. Bolstad has an intro section justifying the Bayesian perspective, as well.

I think I picked that particular set of justifications because educators in general don't care about mathematical proofs, they care about what will be useful for the students to know how to do; in biology, the point of knowing statistics is to be able to read and write scientific papers, and the vast majority of papers are written using frequentist statistics. Proofs will not convince them; the fact that top professors are using Bayesian methods might.

My expectation was that I would replace a mediocre frequentist statistics lecturer with an excellent bayesian statistics lecturer within the same class. The class that I TA is taught by multiple professors, and at least one of them teaches from a Bayesian perspective. Professors have ridiculous academic freedom; one professor covers only basic t-tests, while another professor covers everything from linear regressions to the KS test to chi-squared to two-way ANOVA, and it's still the same course listing. So long as the students aren't complaining about failing, the university does not care. The students can try to sign up for a different professor, and will do so if they hear another prof is easier, but they still have to take the class, so even harder professors still have full sections (especially if their version has a reputation for being very useful/educational).

So, assuming that I would be hired to teach statistics and could choose to teach either frequentist or Bayesian, I see very little point in teaching frequentist. I could also reach vastly more students lecturing than I could via tutoring, probably 80ish vs 10ish.

I think the students that are interested in learning Bayesian stats should have the option available; I think there are probably a fair number of students who are smart, savvy, and motivated enough to sign up for a stronger stats course but aren't quite good enough to teach it to themselves.

I think I would almost rather not teach statistics than teach straight frequentist. I am really sick of teaching kids stuff that I know is suboptimal. I mean, I could do a good job of it, but raising the waterline isn't worth being miserable.

Teaching Bayesian statistics? Looking for advice.

3 tadrinth 24 March 2012 11:40PM

I am considering trying to get a job teaching statistics from a Bayesian perspective at the university or community college level, and I figured I should get some advice, both on whether or not that's a good idea and how to go about it.

Some background on myself: I just got my Masters in computational biology, to go along with a double Bachelors in Computer Science and Cell/Molecular Biology.  I was in a PhD program but between enjoying teaching more than research and grad school making me unhappy, I decided to get the Masters instead.  I've accumulated a bunch of experience as a teaching assistant (about six semesters) and I'm currently working as a Teaching Specialist (which is a fancy title for a full time TA).  I'm now in my fourth semester of TAing biostatistics, which is pretty much just introductory statistics with biology examples.  However, it's taught from a frequentist perspective. 

I like learning, optimizing, teaching, and doing a good job of things I see people doing badly. I also seem to do dramatically better in highly structured environments.  So, I've been thinking about trying to find a lecturer position teaching statistics from a Bayesian perspective.  All of the really smart professors I know personally who have an opinion on the topic are Bayesians, Less Wrong as a community prefers Bayesianism, and I prefer it.  This seems like a good way to get paid to do something I would enjoy and raise the rationality waterline while I'm at it. 

So, the first question is whether this is the most efficient way to get paid to promote rationality.  I did send in an application to the Center for Modern Rationality but I haven't heard back, so I'm guessing that isn't an option.  Teaching Bayesian statistics seems like the second best bet, but there are probably other options I haven't thought of.  I could teach biology or programming classes, but I think those would be less optimal uses of my skills.

Next, is this even a viable option for me, given my qualifications?  I haven't taken any education classes to speak of (the class on how to be a TA might count but it was a joke).  My job searches suggest that community colleges do hire people with Masters to teach, but universities mostly do not.  I don't know what it takes to actually get hired in the current economic climate.

I'm also trying to figure out if this is the best career option given my skillset (or at least estimate the opportunity cost in terms of ease of finding jobs and compensation).  I have a number of other potential options available:  I could try to find a research position in bioinformatics or computational biology, or look for programming positions.  Bioinformatics really makes "analyzing sequence data" and that's something I've barely touched since undergrad; my thesis used existing gene alignments.  I could probably brush up and learn the current tools if I wanted, but I have hardly any experience in that area.  Computational biology might be a better bet, but it's a ridiculously varied field and so far I have not much enjoyed doing research.

I could probably look for programming jobs, but they would mostly not leverage my biology skills; while I am a very good programmer for a biologist, and a very good biologist for a programmer, I'm not amazing at either.  I can actually program: my thesis project involved lots of Ruby scripts to generate and manipulate data prior to statistical analysis, and I've also written things like a flocking implementation and a simple vector graphics drawing program.  Everything I've written has been just enough to do what I needed it to do. I did not teach myself to program in general, but I did teach myself Ruby, if that helps estimate my level of programming talent.  Yudkowsky did just point out that programming potentially pays REALLY well, possibly better than any of my other career options, but that may be limited to very high talent and/or very experienced programmers.

Assuming it is a good idea for me to try to teach statistics, and assuming I have a reasonable shot at finding such a job, is it realistic to try to teach statistics from a Bayesian perspective to undergrads?  Frequentist approaches are still pretty common, so the class would almost certainly have to cover them as well, which means there's a LOT of material to cover. Bayesian methods generally involve some amount of calculus, although I have found an introductory textbook which uses minimal calculus.  That might be a bit much to cram into a single semester, especially depending on the quality of the students (physics majors can probably handle a lot more than community college Communications majors).

Speaking of books, what books would be good to teach from, and what books should I read to have enough background?  I attempted Jaynes' Probability Theory: The Logic of Science but it was a bit too high level for me to fully understand.  I have been working my way through Bolstad's Introduction to Bayesian Statistics which is what I would probably teach the course from.  Are there any topics that Less Wrong thinks would be essential to cover in an introductory Bayesian statistics course?

Thanks in advance for all advice and suggestions!

Comment author: tadrinth 24 March 2012 11:38:09PM 5 points [-]

This paper consists of some vague simulations, followed by wild speculation. I'm pretty sure it's bunk (speaking as a computational/cell biologist). It would be pretty easy to test, as well, as disrupting microtubules AT ALL would completely destroy memories if he is correct.

Comment author: gwern 23 March 2012 04:28:48AM *  19 points [-]

PredictionBook registry - take one prediction a day to keep the hindsight bias away! - based on the speculation:

Harry's solution will be...

(These are not all mutually exclusive, and I didn't set down and make them all sum to 100%.)

Comment author: tadrinth 23 March 2012 11:16:03AM 2 points [-]

Here's another idea: Draco uses his Patronus to tell the assembly he forgives the blood debt. Harry can use his own Patronus to beg Draco to do this.

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