17.2. Reputation domains, entities, and multidimensional reputations

To understand how the Reputation Server accomplishes its task, you have to start with the abstraction of a reputation domain, which is a context in which a sequence of trades will take place and in which reputations are formed and used. A domain is created, administered, and owned by one entity. For example, a consultant integrating the software components for a business-to- business, online e-marketplace might create a reputation domain for that e-marketplace on the Reputation Server. Thousands of businesses that will trade in the e-marketplace can use the same domain. Or someone might create a smaller domain consisting of auto mechanics in Cambridge and the car owners that purchase repairs. Or someone might create a domain for the anonymous servers forming Free Haven.

The domain owner can specify the domain's rules about which entities can join, the definition of reputation within that domain, which information is going to be collected, who can access the data, and what they can access. Reputations form within the domain according to the specified configuration. For the moment, we assume that there is no information transfer among domains: A reputation within one domain is meaningless in another domain.^[4]

^[4] This constraint is relaxed later in the chapter.