vs Caplan, the margin went from -32 to -5, with 7 people dropping out. Do you have some other source of numbers?
If people leave early, that is an extra source of noise, but probably unbiased. If a non-voter is expressing uncertainty, that is a useful source of information, although it would be better to know how many abstain and better if they explicitly expressed uncertainty. I would expect people to be more bashful before the debate than after and am surprised that the number of votes went down.
ETA: the recording of the Eliezer-Hanson debate says that this was an increase in number of undecided people.
Oops, I typed 12 when I meant 32. But I think it's positive 32 and 5, not negative, because he says he won.
Link: overcomingbias.com/2011/07/debating-yudkowsky.html