Transcript PowerPoint - Cornell University

CS 430: Information Discovery
Lecture 5
Descriptive Metadata 1
Library Catalogs
MARC
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Course Administration
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Examples of Library Catalogs
Cornell University Library catalog:
http://catalog.library.cornell.edu/
Library of Congress, Prints and Photographs:
http://www.loc.gov/rr/print/catalog.html
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Descriptive Metadata
Some methods of information discovery search descriptive
metadata about the objects.
Metadata typically consists of a catalog or indexing record, or an
abstract, one record for each object.
• Catalog: metadata records that have a consistent structure,
organized according to systematic rules.
• Abstract: a free text record that summarizes a longer
document.
• Indexing record: less formal than a catalog record, but more
structure than a simple abstract.
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Descriptive Metadata
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Usually stored separately from the objects that it
describes, but sometimes is embedded in the objects.
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Usually the metadata is a set of text fields.
Textual metadata can be used to describe non-textual
objects, e.g., software, images, music
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Descriptive metadata
Information discovery is often most effective when applied to
metadata rather than raw information
• Allows fielded searching
author = "Goethe"
• Suitable for non-textual material
type = "picture" and subject = "Ithaca"
• Can be used with controlled vocabulary
language = "en"
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Origins of Library Catalogs
Bibliographic Objective:
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To bring together like items
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To differentiate among similar ones
Sir Anthony Panizzi, Keeper of Books
at the British Museum (1856-67).
His Ninety-One Rules (1841) were the
basis of modern catalogue rules.
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Origins of Library Catalogs
Information Discovery:
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to enable a person to find a book of which either the
author, title or subject is known
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to show what the library has by a given author, on a
given subject, or in a given kind of literature
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to assist in the choice of a book as to its edition
(bibliographically) or to its character (literary or topical).
Charles Ammi Cutter
Librarian of the Boston Athenaeum
Rules for a Dictionary Catalog, 1874
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Origins of Library Catalogs
Classification:
Division of subject matter into a hierarchy.
Typically used in libraries to provided a subjectbased order for shelving books.
Melvil Dewey
Acting Librarian of Amherst College (1874)
Dewey Decimal system of book
classification, uses the numbers 000 to 999
to cover the general fields of knowledge and
decimals to fit special subjects.
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Technology
Materials to be catalogued:
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Originally books
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Extended to serials, maps, music, etc., but concepts still rely
heavily on experience with books
Form of catalog:
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Entries in books (Panizzi)
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Index cards (Cutter)
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Online databases (Kilgour)
Catalogs as Investments
Costs:
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Conventional Catalog Records are created by skilled librarians.
(cost estimate $100 per record).
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OCLC's catalog has 43 million records. Total investment is
several billion dollars.
Cataloguing Standards:
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Enable libraries to share records
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Combine records of the past with records created today
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Allow readers and librarians to move between libraries
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
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Example: Monograph catalog record
Citation
Caroline R. Arms, editor, Campus strategies for libraries and
electronic information. Bedford, MA: Digital Press, 1990.
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MARC fields
tag value
001 89-16879 r93
050 Z675.U5C16 1990
082 027.7/0973 20
245 Campus strategies for libraries and electronic title statement
information/Caroline Arms, editor.
260 {Bedford, Mass.} : Digital Press, c1990.
publisher
300 xi, 404 p. : ill. ; 24 cm.
collation
440 EDUCOM strategies series on information technology
series title
504 Includes bibliographical references (p. {373}-381).
020 ISBN 1-55558-036-X : $34.95
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MARC fields (continued)
650 Academic libraries--United States--Automation.
subject heading
650 Libraries and electronic publishing--United States.
650 Library information networks--United States.
650 Information technology--United States.
700 Arms, Caroline R. (Caroline Ruth)
040 DLC DLC DLC
043 n-us--955 CIP ver. br02 to SL 02-26-90
985 APIF/MIG
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MARC Encoding
tag:
260
subfield a:
{Bedford, Mass.} :
subfield b:
Digital Press,
subfield c:
c1990.
MARC encoding:
&2600#abc#{Bedford, Mass.} :#Digital Press,#c1990.%
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Name authority files
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Caroline R. Arms or Caroline Ruth Arms?
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Which William Phillips of Cardiff?
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Mark Twain or Samuel Clemens?
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Epithets:
of Cardiff
doctor
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Dates:
1832 - 1876
flourished 1860
circa 1832 - 1876
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Shared cataloguing
OCLC -- Large centralized transaction processing database system
When a library catalogs a book it deposits MARC record in OCLC
Other libraries can copy the record
• saves duplication of cataloguing
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build database of holdings
OCLC database has 43 million records
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Subject information
Library of Congress Subject Headings
Academic libraries--United States--Automation
Hierarchical classification
Library of Congress call number:
Dewey Decimal Classification:
Z675.U5C16
027.7
Creation and maintenance of lists of subject headings and
classifications is a never ending task.
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Online public access catalog (OPAC)
First stage
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Library mounts its MARC records on a central computer
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Provides a simple terminal interface and dedicated terminals
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Boolean search -- fielded searching
[Most university libraries reached this stage about 1990]
Second stage
• Library connects computer to a campus network and Internet
• Converts card catalog records to MARC (retrospective
conversion)
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Library information systems
When the catalog is online ...
Add other collections and services:
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Secondary information (Inspec, Medline, Chemical Abstracts)
Reference works (dictionaries, encyclopedias)
Improve user interface
• Add full text searching
• Add web interface
Add connections to off-campus information sources:
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Scientific journals
Databases (census, genome)
Library management systems
A library management system, sometimes called an integrated
library system, integrates the internal processes of a library, e.g.,
acquisitions, cataloguing, binding, circulation, etc.
It usually contains an online public access catalog, but does not
provide integrated services to users.
Library management systems are produced by small companies
who lack the capital and technical expertise to develop modern
digital libraries.
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Notes on MARC
A great achievement:
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Developed in 1960s
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Magnetic tape exchange format for printing catalog records
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The dawn of computing:
mixed upper and lower case
variable length fields,
repeated fields
non-Roman scripts
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100(?) million records with standard content and format
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Thousands of trained librarians (millions?)
Notes on MARC
A great problem:
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Not designed for computer algorithms
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One record per item (poor links between records)
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Tied to traditional materials and traditional practices
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Not Unicode
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100 of million records at $100 -- $10 billion
A classic legacy system!
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