Data source overview
Unless you are participating in Product Ratings through Google Customer Reviews, you will need to provide a data source if you would like to display product reviews and ratings. This article explains how to properly format your Product Ratings data source.
Note that providing a data source does not guarantee that your content will be included on Google. Your reviews must always comply with our policies.
View an example data source here
XML schema
An XML schema gives guidance on how to structure the XML data source and uses the .xsd file extension. The XML schema reference for Product Ratings is published here.
Refer to the Google Developers' site for more details on the Product Ratings XML schema and data source organization.
XML validation
To ensure that Google can process your data source, use an XML schema validator before submitting your data source.
For more information on validating your data source, visit the XML Validation page on the Google Developers' site.