Metadata and Metamodeling

Authoring, Generation, and Rendering of Metadata

Annotea. Annotea focuses on the management and accessibility of RDF metadata on the server side and does not specify a method of realization and authoring for the clients. Annotation servers are specialized HTTP servers with POST, GET, PUT, and DELETE methods. The POST method creates new annotations while the PUT updates them. The GET method retrieves RDF statements, and the DELETE removes all the annotations associated with a URI.

On the client side, the sample browser Amaya allows users to annotate either the whole document, a section of it, or a specific location within. Users can click in or highlight any part of the document viewed, and type in any remarks. Whether the document is local or remote, based on the URI and the location picked within the document, a RDF statement is generated and submitted to the repository. A new URI is associated with this newly created statement, and any further reference or modification to the statement is made through its URI.

Sesame. Although Sesame does not specify an interface for authoring and browsing metadata, it consists of two modules where clients insert new RDF documents into a repository and retrieve them. These are the Admin and Export Modules. The Admin Module performs insertions incrementally while checking inconsistencies in the repository. The Export Module, on the other hand, simply reconstructs RDF documents retreived from the repository and sends them to any users or client applications.

An electronic notebook (EN) [84] service within SAM and CMCS, provides methods to manage resources and associated metadata. For remote users, the EN service acts as an interface to a network file system with file search, retrieve and save functionality. Within the EN service, a metadata viewer lists attribute-value pairs in a tabular form, while a graphical relationship browser draws a hierarchical chart to project relationships between resources using the special properties, as mentioned previously, hastranslations, children and alike. A metadata generator automatically detects characteristics of resources, such as file sizes, content types, and related resources (i.e. a parent and siblings), and populates metadata while storing it in terms of attribute-value pairs. In addition to metadata generators, application developers can also use programming interfaces to populate metadata within SAM and CMCS.

SAM. SAM also provides a mechanism to register translators to allow users to transform metadata from one format (or schema) into another. Whenever a user wants to browse, or an application accesses to the metadata that belongs to a resource, the client (the user or the application) can activate a registered XSL transformation script and obtain a prefered rendering of the metadata. One can also retrieve metadata (or resource descriptions and relationships) in RDF to exchange with other systems.

IKM. IKM provides an interface to generate metadata, and annotate the resources either in text or by audio recordings. It also allows users to enter the tribal information as well as the rights-related metadata. Metadata and the multimedia content are presented through the Web. The system authenticates users based on the rights metadata and authorizes access to the multimedia content for display using the appropriate media players.