In order to support any of the quality ratings services described above in an RDF environment it is necessary to have mechanisms in place for handling RDF ratings at the following stages:
1. Creation: It must be possible to generate RDF compatible ratings (i.e. ratings that can be expressed in XML-RDF). The exact nature of the generation process is partially dependent on the agent performing the rating (this may be an ordinary user or a service provider). The machine-readable representation of the rating may depend on the mechanism chosen for storage and deployment.
2. Storage and Deployment: Once RDF ratings have been generated they must be stored in a manner that enables the retrieval of the rating associated with a particular resource. The ratings should be deployed using the XML representation of RDF (RDF ratings may or may not be stored directly as XML-RDF up until this point), this provides a common platform for all usage scenarios. The location of and method of access to RDF ratings will depend to some extent on the proposed usage scenario.
3. Usage: Once it is possible to create and deploy RDF ratings as XML-RDF we can consider the usage of those ratings in the provision of quality based services. The technology involved at this stage is highly dependent on the service that is to be provided.
The three stages are not wholly independent, but neither is there a one-to-one correspondence between the options at each stage. For example, RDF ratings created with different metadata editors may be stored in the same database and both embedded and third party ratings may be used to rank search results.
For each of the stages there are existing technologies that can be used or extended in order to support the implementation of quality ratings. These technologies include applications (such as the Netscape browser) that can be used directly and enabling technologies (such as Netscape plug-ins) that can be used to permit or simplify the implementation of new applications. An overview of these technologies is provided as Appendix A of the report.