The question of whether you can trust TripAdvisor for planning overseas adventure travel, or domestic travel for that matter, is an important one for anyone who regularly plans her own trips. The central issue is whether "reader reviews" of a hotel, tour company, or attraction are real. B&Bs have been known to offer people discounts on future stays in exchange for favorable reviews; some hotels have paid people to trash their competitors. A recent Cornell study suggested we might not be very good at detecting fakes and a computer can do better. TripAdvisor has tried to deal with this issue by making more information available about reviewers- how long they have been a member, how many and what reviews they have written etc; and by banning any hotels that clearly manipulate reviews.
There are clearly some red flags to watch out for: excessive use of exclamation points, superlatives, and gushing reviews; reviewers who have only written one review; badly written reviews by someone whose name and location indicates they are from an English speaking country; one poor review among many good ones or vice versa. But the truth is that you can never be completely sure and at best you may be able to get a sense of what people like and dislike about a particular place.
But where TripAdvisor truly shines is their Travelers' Forum. Over the weekend I was planning a hiking trip to Switzerland - this year it's my vacation but I am also scouting it for a new trip next year. I was struggling with the question of needing to book everything in advance and could not find a clear answer on the internet, so I posted a question in the Travelers' Forum. Within 24 hours I not only had an answer, I had a spreadsheet that Stephen (English, living in Switzerland) had put together for his Alpine Pass Route hike plus a link to his blog; and a 20 page mini-travel guide that Kim (American, has visited Switzerland 15 times in 15 years with husband) had put together for her friends. Many of the forums have "Destination Experts" - passionate travelers or locals whose major motivation is sharing their passion.
I'm never going to be a Destination Expert but from now on, I'm going to make sure I post reviews of any hotel or restaurant that stands out - for good or bad. Because in the end, the only way to crowd out fakes is for all of us passionate travelers to share our experience.