US GPOAIP Independence Test CS 496A – Senior Design Fall 2010 Team members: Antonio Castillo, Johnny Ng, Aram Weintraub, Tin-Shuk Wong
Overview • Background • US GPO • FDsys • Project objectives • Hardware interface • Software formats (AIP) • METS, MODS, and PREMIS • XML parsing • Testing • Conclusion
US GPO • The United States Government Printing Office (GPO) is in charge of producing and archiving documents for every branch of the federal government. • “The U.S Government Printing Office (GPO) provides publishing & dissemination services for the official & authentic government publications to Congress, Federal agencies, Federal depository libraries, & the American public.” (http://www.gpo.gov/about/)
FDsys • GPO is developing the Federal Digital System, a new content management system (CMS) designed to manage all of its digital data. • “The U.S. Government Printing Office’s (GPO) Future Digital System (FDsys) will ingest, authenticate, preserve and provide access to digital content from all three branches of the U.S. Government. FDsys, which is in public beta testing, is intended to preserve digital content free from dependence on specific hardware or software.” (project description)
Project Objectives • “The objective of this project is to test whether the AIPs in FDsys are truly independent of the surrounding content management system. The CSULA team aims to either confirm or reject the claim that, with help from resources commonly available to the digital curation community, an interested party could fully reconstruct the archive using only the content data.”
Project Objectives (cont.) • “GPO will supply a set of content data from its archival storage. This data will include content files, metadata files (in XML according to the standards referenced above), and METS binding files (in XML) that describe how all of the objects are related. The CSULA team will inspect the information and, using the METS standard, determine whether the information in XML is sufficient for a user to make sense of the data and ingest it to another repository. Because the data is stored in arbitrary folders, scripts would have to be written to assemble the content packages from the locations specified in the METS file.”
Project Objectives (cont.) • This project simulates FDsys breaking down due to some catastrophic attack or error. • We are attempting to categorize and reconstruct an amount of sample data from FDsys outside the context of the actual CMS. • The only references we have available, other than the actual files in the archive, are publicly defined standards. • It is our hope that this project will help GPO improve the robustness of their file system.
Hardware Interface • A desktop PC computer or notebook with USB/FireWire connection. • External USB/FireWire hard drive containing AIPs exported from FDsys.
AIP • Archival Information Package • Defines how digital objects and its associated metadata are packaged using XML based files. • METS (binding file) • MODS • PREMIS
METS • In order to reconstruct the archive, we will need to understand the METS files. METS is schema that provides a flexible mechanism for encoding descriptive, administrative, and structural metadata for a digital library object. The schema is written in xml format. A METS document consists of seven major sections but we will only need to understand the first five sections to recreate the archive. The last two sections are not used by the U.S. Government Printing Office’s (GPO) Future Digital System (FDsys).
METS Schema • 1) METS Header • The METS Header contains metadata describing the METS document itself, including such information as creator, editor, etc. • 2) Descriptive Metadata • The descriptive metadata section may point to descriptive metadata external to the METS document or contain internally embedded descriptive metadata, or both. This section is link to the MODS xml file.
METS Schema (cont.) • 3) Administrative Metadata • The administrative metadata section provides information regarding how the files were created and stored, intellectual property rights, metadata regarding the original source object from which the digital library object derives, and information regarding the provenance of the files comprising the digital library object. This section is link to the PEMIS xml file.
METS Schema (cont.) • 4) File Section • The file section lists all files containing content which comprise the electronic versions of the digital object. <file> elements may be grouped within <fileGrp> elements, to provide for subdividing the files by object version. • 5) Structural Map • The structural map is the heart of a METS document. It outlines a hierarchical structure for the digital library object, and links the elements of that structure to content files and metadata that pertain to each element.
MODS MODS file will be used to encode descriptive metadata. A MODS file can be used as an extension schema to METS. MODS consist of top-elements elements that are mandatory, recommended or optional.
PREMIS • PREMIS file will be used to encode preservation metadata. • Preservation metadata consists of the following: • Provenance • Authenticity • Preservation activity • Technical environment • Rights management
PREMIS • PREMIS data model includes of the following: • Intellectual Entity • Object Entity • Event Entity • Agent Entity • Rights Entity* • Object, Event, and Agent Entities are described using mandatory and optional elements.