Hey all,

does anyone know what this means? (And it's not the 'given' sign. i.e. it's not that epsilon, given x, is 0 )

$\displaystyle E ( \epsilon | x ) = 0 $

Does it mean that $\displaystyle \epsilon $ is independent of x, and that it's expected value is 0? Or that $\displaystyle \epsilon $ is a function of x? Or something else...?

Thanks.