Montessori Training of Southern Nevada Metadata Research Paper “Describe your opinion” OR “Summarize it”* Word limit: minimum 100 words”Describe your opini

Montessori Training of Southern Nevada Metadata Research Paper “Describe your opinion” OR “Summarize it”* Word limit: minimum 100 words”Describe your opinion” OR “Summarize it”* Word limit: minimum 100 words Understanding
Metadata
What is Metadata? …………………………………………………………………………………….. 1
What Does Metadata Do? …………………………………………………………………….. 1
Structuring Metadata ……………………………………………………………………… 2
Metadata Schemes and Element Sets ……………………………………….. 3
Dublin Core ……………………………………………………………………………………………………… 3
TEI and METS ……………………………………………………………………………………………….. 4
MODS ……………………………………………………………………………………………………….. 5
EAD and LOM ………………………………………………………………………………………… 6
, ONIX, CDWA, and VRA ………………………………………………………… 7
MPEG ……………………………………………………………………………………………. 8
FGDC and DDI ……………………………………………………………………………. 9
Creating Metadata ………………………………………… 10
Interoperability and Exchange of Metadata ….11
Future Directions ……………………………… 12
More Information on Metadata …….. 13
Glossary ……………………………….. 15
Acknowledgements
Understanding Metadata is a revision and expansion of Metadata Made
Simpler: A guide for libraries published by NISO Press in 2001.
NISO Press extends its thanks and appreciation to Rebecca Guenther
and Jacqueline Radebaugh, staff members in the Library of Congress
Network Development and MARC Standards Office, for sharing their
expertise and contributing to this publication.
About NISO
NISO, a non-profit association accredited by the American National
Standards Institute (ANSI), identifies, develops, maintains, and publishes
technical standards to manage information in our changing and ever-more
digital environment. NISO standards apply both traditional and new
technologies to the full range of information-related needs, including
retrieval, re-purposing, storage, metadata, and preservation. NISO
Standards, information about NISO’s activities and membership are
featured on the NISO website .
This booklet is available for free on the NISO website
(www.niso.org) and in hardcopy from NISO Press.
Published by:
NISO Press
National Information Standards Organization
4733 Bethesda Avenue, Suite 300
Bethesda, MD 20814 USA
Email: nisohq@niso.org
Tel: 301-654-2512
Fax: 301-654-1721
URL: www.niso.org
Copyright © 2004 National Information Standards Organization
ISBN: 1-880124-62-9
Understanding Metadata
What Is Metadata?
Metadata is structured information that describes, explains,
locates, or otherwise makes it
easier to retrieve, use, or manage
an information resource. Metadata
is often called data about data or
information about information.
The term metadata is used
differently in different communities.
Some use it to refer to machine
understandable information, while
others use it only for records that
describe electronic resources. In
the library environment, metadata
is commonly used for any formal
scheme of resource description,
applying to any type of object, digital
or non-digital. Traditional library
cataloging is a form of metadata;
MARC 21 and the rule sets used
with it, such as AACR2, are
metadata standards. Other
metadata schemes have been
developed to describe various types
of textual and non-textual objects
including published books,
electronic documents, archival
finding aids, art objects, educational
and training materials, and scientific
datasets.
There are three main types of
metadata:
• Descriptive metadata describes
a resource for purposes such as
discovery and identification. It
can include elements such as
title, abstract, author, and
keywords.
• Structural metadata indicates
how compound objects are put
together, for example, how
pages are ordered to form
chapters.
• Administrative metadata provides information to help
manage a resource, such as
when and how it was created, file
type and other technical
information, and who can access
it. There are several subsets of
administrative data; two that
sometimes are listed as separate
metadata types are:
− Rights management metadata, which deals with
intellectual property rights,
and
− Preservation metadata, which
contains information needed
to archive and preserve a
resource.
Metadata can describe resources at any level of aggregation.
It can describe a collection, a single
resource, or a component part of a
larger resource (for example, a
photograph in an article). Just as
Metadata is key
to ensuring that
resources will
survive and
continue to be
accessible into
the future.
catalogers make decisions about
whether a catalog record should be
created for a whole set of volumes
or for each particular volume in the
set, so the metadata creator makes
similar decisions. Metadata can also
be used for description at any level
of the information model laid out in
the IFLA (International Federation
of Library Associations and
Institutions) Functional Requirements for Bibliographic Records:
work, expression, manifestation, or
item. For example, a metadata
record could describe a report, a
particular edition of the report, or a
specific copy of that edition of the
report.
Metadata can be embedded in
a digital object or it can be stored
separately. Metadata is often
embedded in HTML documents and
in the headers of image files.
Storing metadata with the object it
describes ensures the metadata will
not be lost, obviates problems of
linking between data and metadata,
and helps ensure that the metadata
and object will be updated together.
However, it is impossible to embed
metadata in some types of objects
(for example, artifacts). Also, storing
metadata separately can simplify
the management of the metadata
itself and facilitate search and
retrieval. Therefore, metadata is
commonly stored in a database
system and linked to the objects
described.
What Does
Metadata Do?
An important reason for creating
descriptive metadata is to facilitate
discovery of relevant information. In
addition to resource discovery,
metadata can help organize
electronic resources, facilitate
interoperability and legacy resource
integration, provide digital
identification, and support archiving
and preservation.
Resource Discovery
Metadata serves the same
functions in resource discovery as
good cataloging does by:
• allowing resources to be found
by relevant criteria;
• identifying resources;
• bringing similar resources
together;
• distinguishing dissimilar resources; and
• giving location information.
Organizing Electronic
Resources
As the number of Web-based
resources grows exponentially,
aggregate sites or portals are
increasingly useful in organizing
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links to resources based on
audience or topic. Such lists can be
built as static webpages, with the
names and locations of the
resources “hardcoded” in the
HTML. However, it is more efficient
and increasingly more common to
build these pages dynamically from
metadata stored in databases.
Various software tools can be used
to automatically extract and
reformat the information for Web
applications.
Interoperability
Describing a resource with
metadata allows it to be understood
by both humans and machines in
ways that promote interoperability.
Interoperability is the ability of
multiple systems with different
hardware and software platforms,
data structures, and interfaces to
exchange data with minimal loss of
content and functionality. Using
defined metadata schemes, shared
transfer protocols, and crosswalks
between schemes, resources
across the network can be
searched more seamlessly.
Two approaches to interoperability are cross-system search
and metadata harvesting. The
Z39.50 protocol is commonly used
for cross-system search. Z39.50
implementers do not share
metadata but map their own search
capabilities to a common set of
search attributes. A contrasting
approach taken by the Open
Archives Initiative is for all data
providers to translate their native
metadata to a common core set of
elements and expose this for
harvesting. A search service
provider then gathers the metadata
into a consistent central index to
allow cross-repository searching
regardless of the metadata formats
used by participating repositories.
Digital Identification
Most metadata schemes include
elements such as standard
numbers to uniquely identify the
work or object to which the
metadata refers. The location of a
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digital object may also be given
using a file name, URL (Uniform
Resource Locator), or some more
persistent identifier such as a PURL
(Persistent URL) or DOI (Digital
Object Identifier). Persistent
identifiers are preferred because
object locations often change,
making the standard URL (and
therefore the metadata record)
invalid. In addition to the actual
elements that point to the object, the
metadata can be combined to act
as a set of identifying data,
differentiating one object from
another for validation purposes.
The latter group developed a
framework outlining types of
presentation metadata. A follow-up
group, PREMIS (PREservation
Metadata: Implementation Strategies)—also sponsored by OCLC
and RLG—is developing a set of
core elements and strategies for the
encoding, storage, and management of preservation metadata
within a digital preservation system.
Many of these initiatives are based
on or compatible with the ISO
Reference Model for an Open
Archival Information System
(OAIS).
Archiving and
Preservation
Structuring Metadata
Most current metadata efforts
center around the discovery of
recently created resources.
However, there is a growing
concern that digital resources will
not survive in usable form into the
future. Digital information is fragile;
it can be corrupted or altered,
intentionally or unintentionally. It
may become unusable as storage
media and hardware and software
technologies change. Format
migration and perhaps emulation of
current hardware and software
behavior in future hardware and
software platforms are strategies for
overcoming these challenges.
Metadata is key to ensuring that
resources will survive and continue
to be accessible into the future.
Archiving and preservation require
special elements to track the
lineage of a digital object (where it
came from and how it has changed
over time), to detail its physical
characteristics, and to document its
behavior in order to emulate it on
future technologies.
Many organizations internationally have worked on defining
metadata schemes for digital
preservation, including the National
Library of Australia, the British
Cedars Project (CURL Exemplars
in Digital Archives), and a joint
Working Group of OCLC and the
Research Libraries Group (RLG).
Metadata schemes (also called
schema) are sets of metadata
elements designed for a specific
purpose, such as describing a
particular type of information
resource. The definition or meaning
of the elements themselves is
known as the semantics of the
scheme. The values given to
metadata elements are the content.
Metadata schemes generally
specify names of elements and their
semantics. Optionally, they may
specify content rules for how
content must be formulated (for
example, how to identify the main
title), representation rules for
content (for example, capitalization
rules), and allowable content values
(for example, terms must be used
from a specified controlled
vocabulary).
There may also be syntax rules
for how the elements and their
content should be encoded. A
metadata scheme with no
prescribed syntax rules is called
syntax independent. Metadata can
be encoded in any definable syntax.
Many current metadata schemes
use SGML (Standard Generalized
Mark-up Language) or XML
(Extensible Mark-up Language).
XML, developed by the World Wide
Web Consortium (W3C), is an
extended form of HTML that allows
for locally defined tag sets and the
easy exchange of structured
Understanding Metadata
The Dublin Core Metadata
Element Set arose from discussions
at a 1995 workshop sponsored by
OCLC and the National Center for
Supercomputing Applications
(NCSA). As the workshop was held
in Dublin, Ohio, the element set was
named the Dublin Core. The
continuing development of the
Dublin Core and related specifications is managed by the Dublin
Core Metadata Initiative (DCMI).
The original objective of the
Dublin Core was to define a set of
elements that could be used by
authors to describe their own Web
resources. Faced with a proliferation of electronic resources
and the inability of the library
profession to catalog all these
resources, the goal was to define a
few elements and some simple
rules that could be applied by
noncatalogers. The original 13 core
elements were later increased to
15: Title, Creator, Subject, Description, Publisher, Contributor, Date,
Type, Format, Identifier, Source,
Language, Relation, Coverage, and
Rights.
The Dublin Core was developed
to be simple and concise, and to
describe Web-based documents.
However, Dublin Core has been
used with other types of materials
and in applications demanding
some complexity. There has for libraries is being developed by
historically been some tension the Libraries Working Group.
between supporters of a minimalist
view, who emphasize the
need to keep the elements
Dublin Core Example
to a minimum and the
semantics and syntax
Title=”Metadata Demystified”
simple, and supporters of
a structuralist view who Creator=”Brand, Amy”
argue for finer semantic
Creator=”Daly, Frank”
distinctions and more
extensibility for particular Creator=”Meyers, Barbara”
communities.
Subject=”metadata”
These discussions
have led to a distinction Description=”Presents an overview of
metadata conventions in
between qualified and
publishing.”
unqualified (or simple)
Dublin Core. Qualifiers can Publisher=”NISO Press”
be used to refine (narrow
the scope of) an element, Publisher=”The Sheridan Press”
or to identify the encoding Date=”2003-07”
scheme used in representing an element value. Type=”Text”
The element Date, for Format=”application/pdf”
example, can be used with
the refinement qualifier Identifier=”http://www.niso.org/
standards/resources/
created to narrow the
Metadata_Demystified.pdf”
meaning of the element to
the date the object was Language=”en”
created. Date can also be
Because of its simplicity, the
used with an encoding scheme
qualifier to identify the format in Dublin Core element set is now
which the date is recorded, for used by many outside the library
example, following the ISO 8601 c o m m u n i t y — r e s e a r c h e r s ,
standard for representing date and museum curators, and music
collectors to name only a few. There
time.
All Dublin Core elements are are hundreds of projects worldwide
optional and all are repeatable. The that use the Dublin Core either for
elements may be presented in any cataloging or to collect data from the
order. While the Dublin Core Internet; more than 50 of these have
description recommends the use of links on the DCMI website. The
controlled values for fields where subjects range from cultural
they are appropriate (for example, heritage and art to math and
controlled vocabularies for the physics. Meanwhile the Dublin Core
Subject field), this is not required. Metadata Initiative has expanded
However, working groups have beyond simply maintaining the
been established to discuss Dublin Core Metadata Element Set
authoritative lists for certain into an organization that describes
elements such as Resource Type. itself as “dedicated to promoting the
While Dublin Core leaves content widespread adoption of interrules to the particular imple- operable metadata standards and
mentation, the DCMI encourages developing specialized metadata
the adoption of application profiles vocabularies for discovery
(domain-specific rules) for particular systems.”
domains such as education and
government. An application profile
Understanding Metadata
Page 3
information. SGML is a superset of
both HTML and XML and allows for
the richest mark-up of a document.
Useful XML tools are becoming
widely available as XML plays an
increasingly crucial role in the
exchange of a variety of data on the
Web.
Metadata Schemes and
Element Sets
Many different metadata
schemes are being developed in a
variety of user environments and
disciplines. Some of the most
common ones are discussed in this
section.
Dublin Core
The Text Encoding
Initiative (TEI)
The Text Encoding Initiative is an
international project to develop
guidelines for marking up electronic
texts such as novels, plays, and
poetry, primarily to support research
in the humanities. In addition to
specifying how to encode the text
of a work, the TEI Guidelines for
Electronic Text Encoding and
Interchange also specify a header
portion, embedded in the resource,
that consists of metadata about the
work. The TEI header, like the rest
of the TEI, is defined as an SGML
DTD (Document Type Definition)—
a set of tags and rules defined in
SGML syntax that describe the
structure and elements of a
document. This SGML mark-up
becomes part of the electronic
resource itself. Since the TEI DTD
is rather large and complicated in
order to apply to a vast range of
texts and uses, a simpler subset of
the DTD, known as TEI Lite, is
commonly used in libraries.
It is assumed that TEI-encoded
texts are electronic versions of
printed texts. Therefore the TEI
Header can be used to record
bibliographic information about both
the electronic version of the text and
about the non-electronic source
version. The basic bibliographic
information is similar to that
recorded in library cataloging and
can be mapped to and from MARC.
However, there are also elements
defined to record details about how
the text was transcribed and edited,
how mark-up was performed, what
revisions were made, and other
non-bibliographic facts. Libraries
tend to use TEI headers when they
have collections of SGML-encoded
full text. Some libraries use TEI
headers to derive MARC records for
their catalogs, while others use
MARC records as the basis for
creating TEI header descriptions for
the source texts.
Page 4
Metadata Encoding and
Transmission Standard
(METS)
an encoding format for metadata
for textual and image-based works.
The Digital Library Federation (DLF)
built on that earlier work to create
METS, a standard schema for
providing a method for expressing
and packaging together descriptive,
administrative, and structural
metadata for objects within a digital
library. Expressed using the XML
schema language, METS provides
a document format for encoding the
metadata necessary for management of digital library objects within
a repository and for exchange
between repositories.
The Metadata Encoding and
Transmission Standard (METS)
was developed to fill the need for a
standard data structure for
describing complex digital library
objects. METS is an XML Schema
for creating XML document
instances that express the structure
of digital library objects, the
associated descriptive and
administrative metadata, and the
names and locations of the files that
comprise the digital object.
The metadata necessary for successful
Metadata in Action
management and use of
An oral historian makes tapedigital objects is both more recordings of interviews with members of
extensive than and a particular ethnic group. Interviewees
different
from
the sign a paper release form giving
metadata used for intellectual property rights to the historian.
managing collections of Most interviewees grant permission to
printed works and other disseminate the interviews in print and
physical
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