1. Information modeling and infrastructures for metadata

2. The book catalog
In a paper-based catalog, descriptive information is listed for items.
Typically structured according to a general syntax similar to ISBD
Association with an item is via title or distinguishing mark
Access achieved by scanning the list of entries

3. ISBD
ISBD specifies nine required "areas" of description and a syntax for combining the recorded information
Areas:
0: Content form and media type area
1: Title and statement of responsibility area, consisting of
1.1 Title proper
1.2 Parallel title
1.3 Other title information
1.4 Statement of responsibility
2: Edition area
3: Material or type of resource specific area
(e.g., the scale of a map or the numbering of a periodical)
4: Publication, production, distribution, etc., area
5: Material description area
(e.g., number of pages in a book or number of CDs issued as a unit)
6: Series area
7: Notes area
8: Resource identifier and terms of availability area (e.g., ISBN, ISSN)

4. The card catalog
Descriptive information about an item is recorded on cards
Cards are organized into separate catalogs (file drawers) of different types to enable different access points
Often: Subject / Title / Author
One card per item per catalog
Association to items via shelf numbering scheme
Access via alphabetical search within the catalog corresponding to the access point

5. The special record format approach
Specify a machine-readable record format to hold descriptive information
MARC formats
Bibliographic
Authority
Holdings
Classification
Community

6. Record format – MARC21 Bibliographic
This is a record format specifically designed to encode bibliographic data.
Requires using specialized software to
Load, add, or update records
Index records for catalog search
Typically this software will be an integrated library system (ILS)
Integrates cataloging and maintenance, holdings and circulation, patron information

7. MARC approach One bibliographic record per manifestation (roughly)
Access via OPAC
built from indexing MARC records
Assocation to items via shelf numbers, barcode identifiers, URLs

8. General database approach
Create a relational database to record descriptive information about objects
Specify a schema using a general database model and infrastructure
e.g. create a schema to values of Dublin Core elements
The association between objects and the information structures in the database will depend on the schema design
Access will be achieved via database retrieval tools

9. The relational database approach, intuitively…
The relational approach represents information as a table
… as rows and columns of values.
The rows are considered to be without order.
The columns are considered ordered
Each row typically corresponds to an entity, each column to a property, and the values are specific instances of that property.
A table is a collection of rows (of equal length).
A relational database is a collection of tables.

10. note Schema information is embedded in a relational database
Adding attributes (i.e. columns) requires adjusting the schema
Association to digital objects can be achieved via URIs/URLs/ internal system file locators

11. Document-oriented approaches
Using a general purpose information modeling language, specify a structure for encoding descriptive information about objects
For example, use XML to encode Dublin Core
or use JSON-LD to serialize data in the DPLA
In these approaches you have one "document" per object
But you don't necessarily have one file per object
Access is achieved by building an index across the document collection

12. note
For online resources (especially text), document-oriented metadata can be embedded in the object
XML is a "meta-grammar" for defining schemas
All well-formed XML documents have to match certain requirements
It's not required to have a schema to process XML data, but it helps

13. The digital repository approach
Digital repository software (e.g. Fedora, DSpace) integrates digital asset management and description
Uses a built-in data model to associate digital objects with descriptive information
Standard functions to disseminate or export metadata
Typically as OAI-PMH data

14. Metadata Transport and Aggregation
The purpose is to maintain the integrity of a record across a change in technical environments.
The object of attention is a metadata record (or a set of them).
A system packages up metadata and sends it off to be received by another system.
often using a standard "wrapper" that can be generated in response to a server request
and operates on top of a transmission protocol.

15. OAI-PMH example

16. Metadata Aggregation and Mapping

17. The IPL – LII Merger Issues discussed by Khoo and Hall:
Unique or specialized metadata fields
Lack of item-level metadata
Collections stored in different databases
Lack of controlled subject vocabularies
Lack of hierarchy in browse structures
Incommensurate subject catagories
Complex metadata workflow

18. Discussion
With a partner, choose one of the challenges discussed by Khoo and Hall.
What are the particular consequences of the issue in terms of aggregating metadata?
What kinds of processes might mitigate this challenge?
Khoo and Hall generally point to issues of "institutional knowledge", but how else could these kinds of issues be avoided?

19. Large-scale digital aggregations
Aggregate descriptions of objects
including some “view” of the objects
objects and descriptions are maintained by providing institutions
Cultural heritage aggregations
Europeana
Digital Public Library of America (DPLA)
Promise
Increase exposure of institutions and objects
Wide audience: scholars, teachers, general public

20. Metadata Aggregation Already existing metadata DPLA hub model
harvested and aligned
available through a portal
with links to the providing institution
DPLA hub model
content hubs
provide data directly
service hubs
work with smaller institutions
coordinate digitization and aggregation into DPLA

21. DPLA core data model

22. Item-centric model Portal Platform
Items as focus of description and access
Collection inclusion optional
Collection description limited
Portal
Unified access to millions of items
Humanities, arts, and sciences
Faceted search and visualization
Platform
JSON-LD
RESTful API

23. Dates in DPLA
Date formats vary significantly

24. Date Propagation
DPLA date parsing is unreliable but consistent

25. Subject - Phrases

26. Commonalities and Differences

27. Thresholded Boundaries
Variants
Ojibwe-Ojibway
GLBT-LGBT
Hierarchies
Labor Unions
Minnesota
Minneapolis
Newspapers
Organizing

28. Automatic? Descriptions

29. Automatic? Descriptions