RaaS and Hierarchical Aggregation Revisited

Consumer ratings are widely used in online marketplaces—helping vendors in assessing the quality of offerings and consumers in discovery and purchase decisions. To build trust in a marketplace, which has a direct impact on sales, an accurate assessment of ratings is essential in determining the quality of offerings. This paper proposes novel extensions to consumer Rating as a Service (RaaS)—a rating management service providing consumer rating functionality to a marketplace using hierarchical aggregation, which is a rating aggregation mechanism using hierarchical relationships of components to evaluate composite offerings. Contributions include the optimization of RaaS design for Web-scale, the integration of consumer credibility in hierarchical aggregation, and the application of hierarchical aggregation to existing independent atomic offerings. Various experiments are conducted to demonstrate the practicality of RaaS and correctness of hierarchical aggregation using real ratings from Amazon.com.