Note that when u0 and d0 are zero, or negligible because the total number of votes is large, your posterior expectation is just u/(u+d) -- in other words, exactly the %positive that LW reports when you hover over the score.
(But in practice the total number of votes is rarely large, so the prior matters.)
You’re right, that’s in the second chapter of Gelman too. I’ll edit that.
Note that when u0 and d0 are zero, or negligible because the total number of votes is large, your posterior expectation is just u/(u+d) -- in other words, exactly the %positive that LW reports when you hover over the score.
(But in practice the total number of votes is rarely large, so the prior matters.)