Lifecycle Metadata for Digital Objects (INF 389K)

1. Lifecycle Metadata for Digital Objects (INF 389K) September 18, 2006 The Big Metadata Picture, Web Access, and the W3C Context

2. Anne Gilliland-Swetland, “Setting the Stage” I: Generalities • Content: “library” focus on access • Context: “archives” focus on context of creation and use • Structure: relationships among objects, aggregations of objects, and versions of objects • Note however: these three categories can mix levels--how?

3. Setting the Stage II: Functional types • Administrative • Descriptive • Preservation • Technical • Use • Can you think of other types? Is this a good breakdown? When does each come into play? Who sees them?

4. Setting the Stage III: Attributes • Source of metadata (internal or external) • Method of metadata creation (auto or manual) • Nature of metadata (lay or expert) • Status (static/ long-term or dynamic/short-term) • Structure (structured or unstructured) • Semantics (controlled or uncontrolled) • Level (item or collection or repository)

5. Setting the stage IV: Life Cycle • Creation and [multi-]versioning (administration and description) • Organization (registration, cataloging, indexing) • Searching and retrieval (transactions, system records) • Utilization (rights, version control, annotations) • Preservation and disposition (refresh, test integrity, migrate, expunge…)

6. Gail Hodge, “Understanding Metadata” • Definition: “Metadata is structured information that describes, explains, locates, or otherwise makes it easier to retrieve, use, or manage an information resource.” • Purposes of metadata • Resource discovery (surrogates, cataloging) • Organizing resources (statically or dynamically) • Interoperability (e.g., Z39.50 vs OAI) • Digital Identification (URL, PURL, DOI, Handle) • Archiving and preservation (e.g., PREMIS)

7. Understanding Metadata II: Levels • FRBR distinctions: • Work (a “creation of the mind”) • Expression (one of the possible ways that a creation may be expressed) • Manifestation (one of the possible embodiments of an expression) • Item (an individual exemplar of a manifestation) • Metadata can apply to objects at each of these levels, although all levels may not apply to all possible objects • Note this leaves out aggregates

8. Understanding Metadata III: Sets • Dublin Core (and extensions and profiles) • Text Encoding Initiative (TEI) header • Metadata Encoding and Transmission Standard (METS) • Metadata Object Description Schema (MODS) • Encoded Archival Description (EAD) • Learning Object Metadata (LOM) • Visual Resources Association Core (and CDWA) • MPEG multimedia • INDECS and ONIX

9. Understanding Metadata IV: Creation and Interoperability • Templates, tools, harvesters • Metadata Registries • PRONOM • GDFR • Crosswalks and frameworks (RDF, Semantic Web)

10. Berners-Lee, “Web architecture from 50,000 feet” • Universal information utility: how • Universal addresses: where (URIs) • Universal language: saywhat? (XML) • Action repositories: dowhat? (web services) • Description repositories: who/what (DTDs, schemas, namespaces) • Logical structure for documents (RDF) makes them operable-upon (at a high logical level: B-L wants proofs, not just informal gatherings)

11. XML is for structuring data XML looks like HTML (tags and attributes) XML is text for computers XML is purposely verbose XML is a family XML is only partly new (SGML, HTML) XHTML->XML XML is modular (namespaces) XML is base for RDF, Semantic Web XML is free, universal, supported XML in 10 Points

12. Eric Miller, “Introduction to RDF” • XML provides syntax for RDF • RDF provides structural constraints and a data model for metadata semantics • Means of publishing metadata semantics • Means of combining multiple metadata sets developed for specific purposes • Goal: to enrich metadata available on the Web and make search more precise

13. RDF Data Model • Resources (nodes) • Property-types (relations) • Values (assigned to nodes) • Triples in a directed graph • Can be iterative: each value can in turn be a resource with property-type relations to values • To ensure precision, each reference to a specific semantic set is identified by namespace

14. RDF and metadata vocabularies (namespaces) • RDF/XML schema used for declaring vocabularies (allowed “elements”) and their allowed values (where restricted) • Each metadata set is maintained and made available online via a URI • Metadata registries can gather the metadata namespace definitions or point to them

15. Tim O'Reilly"What is Web 2.0?"

16. So what is it? • Web as platform/service • Harnessing collective intelligence (of users) • Data is the next “Intel Inside”: information as value • End of the software release cycle: perpetual beta, user collaboration • Lightweight programming models: cut and paste, mashups • Software above the single device • Rich user experiences

17. Metadata and the Web (2.0?) • Metadata inside vs outside (but will we seek help with preservation?) • Metadata as value-added (but who adds the value?) • What metadata must be authoritative? • What metadata can never be authoritative? • How important is metadata?