Those probabilities are mostly pulled out of thin air, but I've seen other people use them, so apparently it's expected. Is there some systematic method people use to arrive at them, or do you just sort of look out a window and see what number feels right?
The probability you assign to a hypothesis should accurately represent your degree of belief that the hypothesis is true. Moreover, your degree of belief should be coherent with the rules of probability theory. Unfortunately, we human beings are notoriously bad at probabilistic reasoning. So while there are systematic methods for assigning probabilities based on evidence, it takes a lot of work to use them properly. For a lot of untrained people, myself included, the best we can currently do is see how we feel, attempt to quantify it, and try to constrain it based on rational factors.
If you want to learn more, a few key search words here are "Bayes' theorem," "heuristics and biases," and "debiasing." If you read through the sequences - a daunting task, I know - a lot of it is covered in detail. Or if you'd prefer to read some academic papers and books on the subject, I'm sure I and other users could make recommendations.
The next discussion thread is here.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 85. The previous thread has long passed 500 comments. Comment in the 15th thread until you read chapter 85.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15.
As a reminder, it’s often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: