For hotels, someone I work with who uses TripAdvisor a lot suggested a method I have found is helpful. Select the negative reviews and evaluate the nature of complaints and see if those issues matter to you. For me, mouse in the restaurant is different than I had to wait at check in (I have seen a mouse in a SF hotel restaurant scrambling over a banquette).

Also, one can filter on type of traveler (business vs. Vacation) and that often helps identify reviews that may be more relevant. The biggest issue I find is when the reviewing population has a variety of profiles.