You're looking at Less Wrong's discussion board. This includes all posts, including those that haven't been promoted to the front page yet. For more information, see About Less Wrong.

Fridolin comments on Crazy Ideas Thread, Aug. 2015 - Less Wrong Discussion

7 Post author: polymathwannabe 11 August 2015 01:24PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (240)

You are viewing a single comment's thread. Show more comments above.

Comment author: [deleted] 12 August 2015 03:10:24PM 2 points [-]

What are the meanings of these symbols "EX", "P(X>a)"?

Comment author: cousin_it 12 August 2015 03:26:38PM *  7 points [-]

X is a random variable, E is expected value (a.k.a. average), P is probability. For example, if X is uniformly distributed between 0 and 1, then EX=0.5 and P(X>0.75)=0.25.

Sarunas is saying that some action might not affect the average value, but strongly affect the chances of getting a very high or very low value ("swing for the fences" so to speak). For example, if we define Y as X rounded to the nearest integer (i.e. Y=0 if X<0.5 and Y=1 if X>0.5), then EY=0.5 and P(Y>0.75)=0.5. The average of Y is the same as the average of X, but the probability of getting an extreme value is higher.

Comment author: username2 05 September 2015 11:08:13AM 0 points [-]

This is probably obvious for others, but it wasn't obvious for me that by paying 0.1 to go from the first game to the second one you both decrease your average earnings and increase the probability of high earnings.