Thanks for your questions “Are Yelp reviews useful for finding a great cafe or restaurant”? I think this questions cafe or restaurant is very important for all like yours. Here I’m trying to give your answers in brief.

I answered a similar question on Quora a while back, and I think most of the content of my reply still applies.  I’ve pasted it below, with a few updates and modifications.  In a nutshell, I still think that Yelp reviews are not very useful for finding a great cafe or restaurant for a number of reasons, mostly relating to the reasons people have for posting reviews, and the lack of expertise of the reviewing population.  Here’s the previous answer:

One big problem with Yelp is the psychology involved when submitting reviews.  Generally speaking, there are clusters of people who post reviews on the site.  One group are people who are avid Yelpers.  They spend a lot of time on the site, and post many reviews.  This is a very specific subset of people, and doesn’t have any relation to how much they know about food.  Apart from the avid Yelpers, the main reason people will bother to review a restaurant is to either rant or rave.  If a restaurant is average, most people (apart from avid Yelpers) won’t bother to post.  They’ll only post if they’re angry about a specific experience (very common) or had an amazing one.  This type of polarization greatly skews the information, and makes it not representative of the actual quality of the restaurant.  And a large number of the rants have to do with service issues or personality conflicts/personal problems, so they aren’t motivated by the quality or taste of the food necessarily.

Another big problem is the lack of curating for expertise.  It’s difficult to know objectively which reviews come from people who know a lot about food (or have tastes and priorities similar to yours).  Just because a restaurant appeals to a “foodie” expert, doesn’t mean it will seem great to the average person and even more so vice versa.

Lastly, Yelp will usually have a notable bias against high end restaurants, due to the fact that there will always be some people who simply resent paying that much for meal, and for whom it would be impossible to construct a meal that costs that much.  While some people who are really into food might appreciate a place, those who aren’t as into it will not.  It’s like sending someone to watch an opera who has no interest in the form.  It will be like torture for them, and just make them angry.  At the very least, those reviewers will often set the bar unrealistically high for expensive restaurants because of the chip on their shoulder.

I also agree with other posters about the lack of weighting being an issue.

So between the lack of expertise, the predominance of personal issues, rants and raves on the site, and the inherent sampling biases, Yelp is a pretty poor restaurant review source.  I suggest trying eGullet or Chowhound if you’re looking for a more enthusiast-oriented audience.  Even if you’re not a gourmet, you’ll at least be getting POVs from people who are passionate about food, and not just there to vent.

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