15 ms·
Bayes' Theorem explained by Yudkowsky
- Retric 18y agoIt's always surprising that most people are that bad at math. .01 x .8 /(.01 x .8 + (.99 x 9.6 / 100)) ~= 0.0776 or 7.8%
- tl 18y agoSure, but we expect doctors (who receive much greater education and compensation than most people) to get it right.
- dhbradshaw 18y agoWhat's alarming and interesting isn't that they have a lot of years of school and miss this, but that interpreting diagnostic tests correctly is a core part of their job and they miss it. How many lives are adversely effected and how many billions are wasted by doctors making inappropriate decisions because they don't know how to interpret data correctly?
- Retric 18y agoA few years ago I read that around 50% of all medicine prescribed in the US is providing zero or less net benefit to the patient. Granted by prescribing something doctors get you out of the office and in a few days most things get better on their own. But a lot was simple misunderstanding on the part of doctors about how helpful a given drug actually was.
- michaelkeenan 18y agoIn case you want to find your source, I'm guessing it was economist Robin Hanson: http://www.cato-unbound.org/2007/09/10/robin-hanson/cut-medicine-in-half/ http://www.cato-unbound.org/2007/09/10/robin-hanson/cut-medi...
- Retric 18y agoNo, it was specifically talking about prescribed medicine. Granted not the cost of said medicine. Something like this (http://www.nytimes.com/2008/10/24/health/24placebo.html http://www.nytimes.com/2008/10/24/health/24placebo.html) but rather reviewing what drugs patents where taking and comparing it to their symptoms.
- bd 18y agoAround 15% got it right, which is quite consistent with Sturgeon's Law: http://en.wikipedia.org/wiki/Sturgeon_law http://en.wikipedia.org/wiki/Sturgeon_law
- soldarnal 18y agoAnd in particular with probability. It's amazing how difficult it is for people to fake random data. If you ask half a class to actually perform and record 100 coin flips and half to fake the data, it's almost trivial to guess which is which either by looking for a string of 5-6 heads or tails in a row (which humans almost never have), or by calculating the percentage flips following a heads that are tails (which should be ~50%, but for humans tends to be much higher).
- deleted 18y ago[deleted]
- Retric 18y agoDo significant digits matter in these sort of probability calculations? Yes, but no more than normal. .0051 x .8 / (.0051 x .8 + (.99 x .096)) ~= 4.1% .0149 x .8 / (.0149 x .8 + (.99 x .096)) ~= 11% But, when dealing with cancer those are about the same as 8% aka I want to double check with more tests not having someone cut me open. PS: Be it 99.9999 or .0001% doctors only ever know a probability. Which is why they want to "run more tests".
- kirse 18y agoDo significant digits matter in these sort of probability calculations? Secondly, do we want doctors to tell us the probablility estimate that we have cancer or do we want doctors to tell us Yes or No? Personally, I don't care what my probability score is if the answer is "No". Even if the answer was "Yes", an optimistic person would ignore the odds anyway.
- gjm11 18y agoYes, I want the probability estimate, because I want the best information available in that sort of situation. And the word for someone who ignores the odds is not "optimistic" but "foolish", unless the answer makes no difference to your behaviour. (Which is pretty unlikely in the case of cancer.)
- aswanson 18y agoWent back and re-read his tribute to his brother/exhortation to move forward science again. It's like You and Your Research on steroids. If that essay doesn't motivate you, I don't know what will. Insanely brave.
- anewaccountname 18y agolink?
- yters 18y agoHas someone figured out a way around the 2nd law of thermodynamics? Or is it not a law anymore? I'm not a physicist, so I don't know these things.
- rms 18y agohttp://www.multivax.com/last_question.html http://www.multivax.com/last_question.html
- yters 18y agoThat's a sci fi story, not hard science. Absolutely nothing integral to the singularitrons' vision has been demonstrated to any extent. Instead, the opposite is shown by the fact cpu speeds have leveled out.
- herdrick 18y ago[java applet] [java applet] [java applet] [java applet] [java applet]
- herdrick 18y agoWhich is not to say you shouldn't click! In fact these are the most useful Java applets I've ever seen. He still should've done them with Flash, though.
- deleted 18y ago[deleted]
- rms 18y agoThis is my favorite writing by Yudkowsky: http://www.overcomingbias.com/2008/05/faster-than-ein.html http://www.overcomingbias.com/2008/05/faster-than-ein.html
- jcl 18y agoIt bugs me a little that he starts using the phrase "prior probability" before defining it. If your vocabulary already included the word "priors", you probably wouldn't need a Bayes tutorial. :)