I honestly don't think that the kinds of places we frequent are prone to falsely planted reviews. We don't often go to high profile places that would wage ratings wars with each other. Our kind of restaurants are small local places in smaller cities. We're not naive about how to interpret reviews; we always discount the ones written by people who complain about everything or the ones that are too complimentary. What we look at primarily is the distribution of reviews across ratings categories. At most decent places the number of low ratings will decrease as the rating level decreases. In other words there will be fewer 2-star ratings than 3-star and fewer yet 1-star ones. What we try to avoid are those places that have a cluster of very poor ratings that "clump" near the bottom. That often seems to indicate an inconsistency of performance which results in some "really bad" days. If a restaurant has more than a handful of reviews it is unlikely that a significant fraction of them will be "plants" anyway. Like any other statistical analysis problem, as the number of samples gets larger the true distribution becomes more evident. I rarely pay that much attention to any particular review but, rather, I look to see where the average rating is. IMHO most restaurants end up with averages in the 3-4 star range. We try to look for those that rate 4+ or higher.