[thanatropism]

Individual preferences cannot be aggregated into something that resembles a preference ranking. The most cited formalization of this is Arrow's impossibility theorem, but choice aggregation is this whole theory.

_Judgement_ is a slightly different problem. There's an entire issue (#145) of the _Journal of Economic Theory_ on this, but the panorama is still quite bleak, and the reddit approach is far from state-of-the-art.

(Personal experience: I've "returned" to reddit (I swore off facebook but I'm still addicted to having something on my phone), and the only way to get people to interact with you is to browse the "new" queue. Once something is "hot" it's basically dead -- new comments are queued to the end even if they're rising fast, and no one replies to you).

[zolloie]

The flaw with that line of criticism is that it makes assumptions about the meaning of the ratings. Note, too, that Arrow's impossibility theorem applies to ranking but not ratings. That also applies to a very simplified, idealized case which can be superceded by more sophisticated voting/rating systems.

[bo1024]

Yes, but single-peaked preferences are a special case that apply here, and where the median is truthful.

(For those not familiar: single-peaked preferences assumes that the person always prefers the final rating to end up closer to their personal rating. So if I believe the restaurant is 3 stars, I'd most prefer it gets rated actually at 3 stars, and I'd rather see 2 stars than 1 star. If all the raters have single-peaked preferences, then using the median to produce the final rating is truthful: A person can't move the final rating closer to their own belief by lying. The mean is not truthful: If the current average is 4 and my rating is 3, I can pull the average closer to 3 by giving a 1-star review.)