An Archival Submission       Information Package for E-Journals

E-Journal Archive

	Mellon E-journal archive project
		http://www.diglib.org/preserve/ejp.htm
	“Preserve significant intellectual content … independent of the form originally delivered�
	Publisher, not subject based
	Multiple external content suppliers
	Initially dark content

Design Principles

	Issue-centric
	Capture content at highest resolution, finest granularity, most abstract representation
		Archiving work, not manifestation
	Architecture based on OAIS
	Acceptance by stakeholders is cost-sensitive
		Automation
		Standards
		Homogeneity

Find Efficiencies Wherever Possible!

What Is OAIS?

	Open Archival Information System
		http://ccsds.org/documents/pdf/CCSDS-650.0-R-2.pdf
	“A common framework of terms and       concepts … to provide long-term       preservation of digital information�
	An functional and information reference      model

OAIS Functional Model

OAIS Information Model

Archival SIP

	Unit of submission is the e-journal issue
	Modeled at two levels: issue and item
	Explicit separation of content and metadata
	METS used for metadata
	XML DTD for item content under development by Harvard and NLM, based on PMC2 DTD

Normative Data Formats

	Necessary for internal data homogeneity
	Single format for each content category
		Text is XML, raster still image is TIFF, ...
	Standards, maturity, viability, robust tools, created upstream in production process
	Lower level specification than MIME type
		Bi-tonal TIFF with Group IV compression
	Non-normative formats transformed on ingest

Format Registry

	Version history
	Authoritative specification / maintenance org.
	Identity characterization
		MIME type, magic number, internal syntax
		Application specific profile
	Technical metadata schema
	Compliant tools
	Community-wide resource and responsibility

SIP Directory Structure

What Is METS?

	Metadata Encoding & Transmission Standard
		http://www.loc.gov/standards/mets/
	“A standard for encoding descriptive, administrative, and structural metadata   regarding objects within a digital library�
	DLF funded; maintained at LC MARC Standards Office

METS Schema

	Namespace-qualified XML schema
		http://www.loc.gov/standards/mets/mets.xsd
	Explicit structural metadata; containers for externally-defined descriptive and administrative metadata (“extension schemas�)
	External pointers using XLink; internal links via ID/IDREF

Why METS?

	Why not use RDF, Topic Map (ISO/IEC 13250), or a custom schema?
	METS is designed specifically for library-like digital objects
	Appropriate technology with pre-defined semantics
	Community support

METS Structure

SIP Hierarchical Structure

SIP Metadata

	DMD based on MODS (or MODS-like)
	Where does technical metadata come from?
	Item-level rights metadata overrides issue-level metadata
	Provenance and source metadata not used
	Structural metadata explicitly defined by SIP specification

SIP Details

	File and internal ID naming conventions designed to make SIP self-documenting
	Non-ASCII Unicode entered as XML numeric entities; non-Unicode as character entities
	SIP is aggregated and compressed into a JAR file for submission
	Full SIP specification (Version 1.0 DRAFT)
		http://www.diglib.org/preserve/harvardsip10.pdf

METS Java Toolkit

	Procedural construction and parsing of METS files
		http://hul.harvard.edu/mets/
	Java API
	Local and global validation
	Marshal/unmarshal
		Serialize in-memory representation to file
		De-serialize from file to in-memory representation

Toolkit Implementation

	Generic API
		Can be sub-classed for application-specific behavior
	Based on Sun’s JAXB specification
		http://java.sun.com/xml/jaxb/
	Uses Jim Clark’s XP parser
		http://jclark.com/xml/xp/

Procedural Construction

METS Automation Tools

	For depositors:
		Construction of partial METS files
			Still need to add specific metadata
		Pre-deposit validation
		API integration into existing content management and production systems
	For the archive:
		Parsing and validation during ingest
		Ingest conversion of SIP to AIP
		Access conversion of AIP to DIP

Are These Standards Helpful?

	OAIS
		Common vocabulary for inter-project and inter-disciplinary conversation
		Conceptual mapping between heterogeneous systems
	METS
		Appropriate technology
			Not a universal panacea; but sufficient for library-like resources and processes
		Community support

Questions?

	Mellon E-Journal Archiving Project
		http://www.diglib.org/preserve/ejp.htm
		http://www.diglib.org/preserve/harvardsip10.pdf
	OAIS
		http://ccsds.org/documents/pdf/CCSDS-650.0-R-2.pdf
	METS
		http://www.loc.gov/standards/mets/
		http://hul.harvard.edu/mets/
	stephen_abrams@harvard.edu