This document is for listing existing formats for specifying aggregate review information.
So far, no such formats have been found.
Here are some sites that attempt to aggregate reviews from many sources including other aggregators (without the benefit of any accepted standard):
- Wize.com: they have collected reviews from many aggregators. For example, the [Nuvi 260W] review shows aggregate review scores from Amazon, Bestbuy, and Pcnation, and they collect review data from other sites (i.e. Dell, Shopping.com) as well. There is no documentation indicating that they use a standard schema to acquire this data.
- Metacritic: Metacritic aggregates reviews across sites, but does not collect data from critics in any standard way. Instead, they adapt to the various critics' review styles and manually assign standardized scores to each, which they then aggregate. They also collect user reviews on their own site, but don't attempt to collect aggregate user review data from other sites.
- Google Maps: shows reviews for local businesses collected from a variety of sites but does not have any per-site aggregate information (i.e. 35 Zagat reviews, 17 Yelp reviews, 21 Insiderpages reviews).