1. Lecture 12 Why metadata?
CS 502 Computing Methods for Digital Libraries Cornell University – Computer Science Herbert Van de Sompel

2. Notes
Carl Lagoze on Wednesday
No Lab on Friday
But Paul Ginsparg on 04/03
XML Schema & XSLT - later

3. Content – Data - Metadata
Content refers to digital library materials as information that is of interest to a user.
Data emphasize bits and bytes to be processed by a computer.
Metadata : data about data

4. Metadata – focus on description/discovery
data about data
origins in library cataloguing, A&I databases
now: an amplification of traditional bibliographic cataloguing practices in an electronic environment;
now: any data used to aid the identification, description and location of networked electronic resources.
actually, it is more

5. Metadata - broader
descriptive: facilitating resource discovery and identification (record in OPAC system)
administrative: facilitating resource management within a collection (loan record in OPAC system)
structural: binding together the components of complex information objects (series title in record in OPAC system)

6. descriptive/discovery
Metadata - evolution
descriptive/discovery
library objects
descriptive/discovery
administrative
structural
library objects
networked resources

7. Metadata
Traditionally stored separately from the objects that it describes,
For digital objects, sometimes is embedded in the objects (cf. KWF).
Usually the metadata is a set of text fields.
Textual metadata can be used to describe non-textual objects, e.g., software, images, music, …

8. Metadata – why?
Some methods of information discovery search descriptive metadata about the objects.
Generally, it enables digital library services:
explicitly (discovery metadata) or implicitly (terms and conditions)
helps to impose order on chaos
enables automated discovery/manipulation of objects

9. Metadata – generation (traditional)
cataloguing rules
object
metadata record
reference data

10. Metadata – generation (traditional)
Advantage:
Human expertise leads to high-quality catalogs and indexes
Disadvantages:
Expensive ($50+ per record)
Time consuming
Requires cumbersome cataloguing rules
Slow to adapt to new formats and types of digital objects
Human cataloging and indexing is too expensive to apply to all but a small proportion of digital objects
=> automatic generation of metadata

11. Metadata – roots (Library cataloguing)
Anglo American Cataloguing Rules (AACR2)
• rules for what goes into each field of a catalog record
MARC format
• an exchange format for catalog records
"MARC Catalog"
• catalog in MARC format, where content of each field
follows AACR2

12. Citation: a monograph -- book!
Caroline R. Arms, editor, Campus strategies for libraries and electronic information. Bedford, MA: Digital Press, 1990.

13. MARC tags
MARC subfield code
MARC subfield
MARC field
MARC indicator

14. ISBN
Title statement
Imprint –
location,
publisher,
year
Collation
Series Title

15. directory
leader
field
terminator
001 field

16. MARC: the good news
A great achievement:
Developed in 1960s
Magnetic tape exchange format for printing catalog records
The dawn of computing:
mixed upper and lower case
variable length fields,
repeated fields
non-Roman scripts
100(?) million records with standard content and format
Thousands of trained librarians (millions?)

17. MARC: the bad news
A great problem:
Not designed for computer algorithms
One record per item (poor links between records)
Tied to traditional materials and traditional practices
Not Unicode
100 million records at $50+/record
A classic legacy system!

18. Metadata –- simplicity/complexity
Variety of metadata formats for description/discovery:
basic, proprietary, records used in global internet search services;
simple attribute/value records such as the ROADS templates used in eLib subject services;
unqualified Dublin Core (12 elements only)
the more structured TEI and MARC formats;
qualified Dublin Core
detailed formats such as CIMI and EAD, typically applied to archival material.

19. Metadata –- one-size-fits-all/application-profiles
There is an evolution from a “one size fits all” concept for metadata towards:
the use of a specific format depending on the purpose;
the co-existence of formats in relation to an object;
combining metadata elements from various formats;
Choice of format can depend on:
the functional purpose of the metadata –- [description/ discovery/location] ; [administration] ; [structuring]
level of detail required to fulfill the purpose
discipline/domain/audience of the objects that are described
legacy issues
interoperability requirements

20. Internet Commons Metadata – interoperability Commerce Home Pages
Whatever...
Home
Pages
Geo
Internet
Commons
Library
Museums
Scientific
Data

21. Metadata – descriptive/other
There is an evolution towards the creation of standards for non-discovery related metadata formats:
Preservation metadata [NedLib, CEDARS, …] (see OCLC overview document -
Data Dictionary for Technical Metadata for Digital Still Images“ (
book e-commerce [ONIX]
resource administration:
Circulation Interchange Protocol (NCIP) Standard – see
Electronic resources (cf. Adam Chandler)