<research scientist hat>
if you add polls to old review threads now:
-- you won't have the same people who posted in those threads voting, so you don't get a good representation of the reviews.
-- what people vote a year (for example) after they've read a book would statistically be different from what they would vote straight after they've read a book. so the ratings would mean different things.
so, I would discourage adding polls to old threads, but rather have new polls for them, and have the ratings in a different table.
</research scientist hat>
Hmm. Those are good points. OTOH, my page is already liable to alter the dynamic of older polls: If I keep making posts while having the link to it in my signature, new people are invariably going to find the polls and vote in them. So we're going to see poll participation by non-posters anyway, and might as well extend that to "new old" threads, no?
Of course this does raise the issue whether my page is a problem because it interrupts the synergy between thread posts and poll votes. But I'd say lets not be afraid of a little change
. Plus there never was a mechanic that required
posting to poll - and I know that I, as a relatively new arrival, intended to vote in the older polls once I've read those books even prior to making the page.
Plus, there's something that might offset the problem specifically related to poll grafts: Thread subscriptions. The folks who posted in those threads would get notified of the new reply yielded by the merge, I think, and might thus vote after all. Or we could add a second reply specifically to provoke that.
If all else fails, I think the forum population is relatively
stable, so the intersection between folks watching the traffic back then and watching the traffic now is pretty large. If they see those threads pulled back up and check out the new post, they're going to vote. Especially if we include something in the posts to encourage them, pointing out this consideration.
So all things considered I'd prefer the poll graft option myself