The Making of America Testbed Project, coordinated by the Digital Library Federation (DLF), is a multiphase endeavor. Its purpose is to investigate important issues in the creation of an integrated but distributed digital library of archival materials (that is, digitized surrogates of primary source materials found in archives and special collections). Drafted during the MoA II planning phase, this report identifies a starting point for the testbed that is being created in the production phase of this project, which is funded by the National Endowment for Humanities.
The library community has a distinguished history of developing standards to enhance the discovery and sharing of print materials: they include, for example, MARC, Z39.50,and interlibrary loan protocols. This leadership continues today, as libraries create new best practices and standards that address digital collections and content issues. The primary goal of this report is to open a dialogue about digital library standards, specifically, to discuss any new best practices and standards that will be required to enable the digital library to meet traditional collection, preservation, and access objectives.
This report asks the question, “How can we create integrated digital library services that operate across multiple, distributed repositories?” Existing standards and best practices clearly play an important role in answering this question. However, this report and the MoA II Testbed Project raise a new area of discussion that goes beyond the discovery of a digital object and address how it is handled. The report and the testbed focus on the need to develop standards for creating and encoding digital representations of archival objects (for example, a digitized photograph or a digital representation of a book or diary). If tools are to be developed that work with digitized archival objects across distributed repositories, these objects will require some form of standardization.
This report begins the discussion of digital object definitions by developing and examining metadata standards for digital representations of a variety of archival objects, including text, digitized page images, photographs, and other forms. For the purposes of this report, there are three types of metadata: descriptive, structural, and administrative. Descriptive metadata are used to discover the object. A researcher may use descriptive metadata to limit a search by title and author in an OPAC or other database. Structural metadata define the object’s internal organization and are needed for display and navigation of that object. For instance, structural metadata may contain information about the number of pages an object contains and what order they should be viewed in. Administrative metadata contain the management information needed to keep the object over time and to identify artifacts that might have been introduced during its production and management. For example, administrative metadata indicate when the object was digitized, at what resolution, and who can access it.
The project testbed proposes to use existing descriptive metadata standards, such as MARC records and the Dublin Core, as well as standards that incorporate both descriptive and structural metadata, such as the Encoded Archival Description (EAD), to help the user locate a particular digital object. This report proposes defining new standards for the structural and administrative metadata needed to view and manage digital objects.
At a higher level, the report proposes a Digital Library Service Model in which services are based on tools that work with the digital objects from distributed repositories. This approach borrows from the popular object-oriented design model. It defines a digital object as encapsulating content, metadata, and methods. Methods are program code segments that allow the object to perform services for tools (for example “Get the next page of this digital diary”). Unlike other models, the Digital Library Service Model includes methods as part of the object.
The report also identifies several archival digital object classes that are being examined as part of the MoA II project, including photographs, photograph albums, diaries, journals, letterpress books, ledgers, and correspondence. One of the objectives for the testbed is to develop the tools that display and navigate these MoA II objects, some of which have complex internal organization. Therefore, another goal of this report is to identify the structural metadata elements that are needed to support display and navigation and ensure that they are included as part of the digital objects. Finally, this report begins to examine the methods (program code) that could be included with each class of object.
After the library and archival communities have reviewed this report, MoA II participants will incorporate reader feedback into the development of digital object definitions for the classes of materials to be examined in the MoA II testbed. These definitions will specify how to encode the content, metadata, and methods as part of the object. An important goal of the project is to use the testbed to investigate the advantages and limitations of these definitions and stimulate discussion of standards for digital library objects and best practices for digitizing archival materials. This discussion must include the project participants, DLF members, and representatives of the wider community. In addition, the project will contribute to the DLF Architecture Committee’s ongoing discussion of distributed system architectures for digital libraries. The MoA II testbed will give the library and archival communities a tool they can use to test, evaluate, and refine digital library object definitions and digitization practices. It is expected that these discussions will move the archival and library communities closer to a consensus on standards and best practices in these areas.