Nosto for Shopify supports ratings and reviews powered by Bazaarvoice. In order to begin leveraging Bazaarvoice's ratings and reviews in Nosto, you'll need to install Bazaarvoice's app for Shopify.
Once you have installed and configured Bazaarvoice on your Shopify store, you'll need to contact our support personnel who can enable the integration for you. This is a one-time operation after which Nosto begins collecting the rating and review metadata automatically. There is no additional configuration required on Nosto's end.