We recently discovered Yelp's hidden "filtered" review section, and Lifehacker reader DragonPhyre lets us know of another good method for making an informed decision: take angry, negative reviews at half value.
I take bad reviews at half-rating... and I take good ratings at slightly more than normal. Why? It has been my experience that I am far more likely to leave a scathing negative review than a positive one because if I am happy or content, I forget to tell anybody online about it. If I feel slighted or I feel that people should know about a particularly negative aspect of something, then I leave reviews.
Now, everyone's different, but I've found that negative reviews -- especially when there are only a few reviews to pick from -- tend to be less trustworthy. Plus, a lot of people seem to think that if a product has any cons, it deserves a one-star rating... which makes no sense (see the image above for an example).
Of course, you could expand this tip to include positive reviews that seem fake or planted too, or anything else you generally want to filter out. If nothing else, it will help you get a better idea of which reviews you trust and which ones look like baloney.