$\begingroup$
$\endgroup$
5
I was reading through a paper, when I encounter p(a|s). What does this mean? It was in context with log probability but I cant find this notation anywhere.
3 Answers
$\begingroup$
$\endgroup$
That is standard notation for conditional probability.
See here for example for further information.
$\begingroup$
$\endgroup$
2
The notation P(x|y) means P(x) given event y has occurred, this notation is used in conditional probability.
There are two cases if x and y are dependent or if x and y are independent.
Case 1) P(x|y) = P(x&y)/P(y)
Case 2) P(x|y) = P(x)
$\begingroup$
$\endgroup$
Like everyone else said, it's just notation for conditional probability. Here is the textbook that I used last semester in my probability class. Flip to page 141 and you can read all about the conditional probability, both in discrete and continuous cases.
