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Chapter 2. Understanding Metadata Vocabularies

Chapter 2 section titles

2.1 Metadata Element Sets
2.1.1 Components and Structures – An Overview
2.1.2 Flat Structure
2.1.2.1 Dublin Core Metadata Element Set
2.1.2.2 VRA Core 3.0
2.1.3 Nested Structure
2.1.3.1 VRA Core 4.0
2.2 Application Profiles
2.2.1 The Concept of Application Profile (AP)
2.2.2 Examples of APs Consisting of Elements Drawn from Other Schemas
2.2.3 Sources of Reusable Elements
2.3 Ontologies as Metadata Vocabularies
2.3.1 Background
2.3.2 Modular Structure
2.3.3 Friend of a Friend (FOAF)
2.3.4 Schema.org
2.4. RDF Vocabularies for Metadata Terms
2.4.1 An Introduction to RDF (Resource Description Framework)
2.4.2 DCMI Metadata Terms
2.4.3 Metadata Descriptions: From “Records” to “Statements”
2.5 Conclusion

Links to sources

Red star* = newly updated* or added**

Figure 2-1-1 An entry for DC element date ..... 40

Figure 2-1-2 An entry for VRA Core 4 (Restricted Version) element title ..... 42

Figure 2-1-3 The 15 Dublin Core elements seen from three categories, composed based on Weibel, et al. 1998 Section 2. (p.2) and DCMES, Version 1.1..... 46

Figure 2-1-5 VRA Core 4.0 elements and sub-elements, composite based on VRA Core 4.0 Element Outline 2007 (pdf)..... 53

Figure 2-2-3 Portion of the metadata elements within the NSDL_DC metadata framework, from NSDL_DC Metadata Guidelines, Section IV. 1. NSDL_DC metadata fields ..... 59

Figure 2-3-1 The Semantic Web Layer Cake: Tim Berners-Lee. 2000 . and W3C Latest layer cake diagram..... 62

Figure 2-3-2 A FOAF file for a Person instance. Created using the tool FOAF-a-Matic and validated with the W3C RDF Validator..... 65

Figure 2-3-3 Explanation of the Schema.org Types (or "classes") Hierarchy view and an Individual Type view of "Book" type ..... 67

Figure 2-4-5 RDF serialization formats at a glance, generated based on "What's New in RDF 1.1"..... 73

Figure 2-4-6 dcterms:creator ..... 75

Figure 2-4-8 dcterms:accrualPeriodicity's domain and range ..... 77

URLs provided in the chapter, including:

DCMI Metadata Terms (DC Terms) https://dublincore.org/documents/dcmi-terms/

** DCMI Today (a video, 2021) - from Metadata 1.0 to Metadata 3.0

Linked Open Vocabularies (LOV) https://lov.linkeddata.es/dataset/lov

FOAF Vocabulary Specification 0.99 http://xmlns.com/foaf/spec/

Schemas in Schema.org (https://schema.org/docs/schemas.html)

W3C RDF Validator https://www.w3.org/RDF/Validator/

EasyRdf converter https://www.easyrdf.org/converter

RdfSyntax https://www.w3.org/wiki/RdfSyntax

Library of Congress Linked Data Service https://id.loc.gov

Austen, Jane (English writer, 1775-1817) - VIAF ID: 102333412 ( Personal ) & Permalink: http://viaf.org/viaf/102333412

Exercises

For each section, read the documentation provided by the owners of the metadata standards (e.g., DCMES, VRA Core 4.0, Schema.org, and DC Terms), focusing primarily on the specifications of each element set and its user guide. Pay attention to the ways in which an element is defined in each standard. Ignore XML schemas of these standards that are prepared for machine processing for now.

See also exercises and resources for the textbook, including:

Readings

Baker, Thomas. 2012. "Libraries, Languages of Description, and Linked Data: A Dublin Core Perspective." Library Hi Tech 30 (1):116−33.

Guha, R. V., Dan Brickley, and Steve Macbeth. 2015. “Schema.org: Evolution of Structured Data on the Web.” ACM Queue 13 (9). https://queue.acm.org/detail.cfm?id=2857276.

Harper, Corey. 2010. "Dublin Core Metadata Initiative: Beyond the Element Set." Information Standards Quarterly 22 (1):21−28. http://www.niso.org/publications/isq/free/FE_DCMI_Harper_isqv22no1.pdf.

Heery, Rachel, and Manjula Patel. 2000. "Application Profiles: Mixing and Matching Metadata Schemas." Ariadne, no. 25. http://www.ariadne.ac.uk/issue25/app-profiles/.

Schreiber, Guus, and Yves Raimond, eds. 2014. “RDF 1.1 Primer.” W3C Working Group Note 24 June 2014. http://www.w3.org/TR/rdf11-primer/.

Weibel, Stuart, Jean Godby, Eric Miller, and Ron Daniel. 1995. “OCLC/NCSA Metadata Workshop Report.” http://xml.coverpages.org/metadata.html.

Takeaways

1. In an element set, each element
should have
at least these basic components:
element ID, name, label,
definition,
comment (best practices and data value restriction),
and reference.

 

2. Creators of metadata specifications must make decisions on:
- Elements and their structures (relationships between elements)
- Constraints on elements AND content.

Elements in a metadata standard can be organized
in a flat, nested, or modular style.

 

3. In an Application Profile (AP), the elements may be from one or more element sets, thus allowing a given application to meet specialized and/or local functional requirements.

- Consider reuse of elements in existing standards to avoid reinventing the wheel.


4. There are metadata vocabularies that
have been described as:
- ontologies,
- schemas, and
- RDF vocabularies.

They are encoded with OWL (Web Ontology Language) and RDF serialization formats.