1 / 28

CS 430 / INFO 430 Information Retrieval

CS 430 / INFO 430 Information Retrieval. Lecture 16 Library Catalogs 1. Course Administration. Information Retrieval with High Recall. Full-text Indexing (automated)

hasad
Télécharger la présentation

CS 430 / INFO 430 Information Retrieval

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CS 430 / INFO 430 Information Retrieval Lecture 16 Library Catalogs 1

  2. Course Administration

  3. Information Retrieval with High Recall Full-text Indexing (automated) • Text only. Most effective on medium-length documents on related topics. High recall requires tuning system to the specific collection and skilled users. Catalogs and Indexes (created manually) • Can be used for all formats of material • Requires close quality control of metadata creation • High recall requires tuning system to the specific collection and skilled users.

  4. Descriptive metadata • Information discovery is can be very 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" (English)

  5. 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

  6. Origins of Library Catalogs Bibliographic Objective: • To bring together like items • 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 catalog rules.

  7. Origins of Library Catalogs Information Discovery: • to enable a person to find a book of which either the author, title or subject is known • to show what the library has by a given author, on a given subject, or in a given kind of literature • 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

  8. Origins of Library Catalogs Classification: Division of subject matter into a hierarchy. Typically used in libraries to provided a subject-based 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.

  9. Technology Materials to be catalogued: • Originally books • Extended to serials, maps, music, etc., but concepts still rely heavily on experience with books Form of catalog: • Entries in books (Panizzi) • Index cards (Cutter) • Online databases (Kilgour)

  10. Catalogs as Investments Costs: • Conventional Catalog Records are created by skilled librarians. (cost estimate $100 per record). • OCLC's catalog has 52 million records. Total investment is several billion dollars. Cataloguing Standards: • Enable libraries to share records • Combine records of the past with records created today • Allow readers and librarians to move between libraries

  11. Shared Cataloguing: OCLC • 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 • build database of holdings • OCLC database has 52 million records, serves 47,000 libraries • When developed in 1967, OCLC was a pioneering computer system (had to develop own network, computer terminal, etc.)

  12. Layers of a Library Catalog Encoding • Rules that define how catalog records are encoded in a computer system, e.g., XML mark-up. Syntax • Rules that define the fields and subfields, whether repeated, optional, etc. Semantics • Rules that define the values of the field and subfield, with instructions for cataloguers of what data to include and how to decide when choices have to be made.

  13. Library Cataloging using the Anglo American Cataloguing Rules Anglo American Cataloguing Rules (AACR2) • Rules for each category of material, e.g., monographs (books). Specify what fields should be used and what data to include in each field. Text strings were originally intended for printed catalog cards. MARC format • An exchange format for catalog records. Includes encoding rules and syntax specification. "MARC Catalog" • Catalog in MARC format, where content of each field follows AACR2.

  14. Anglo American Cataloguing Rules The Anglo American Cataloguing (AACR) rules provide detailed rules for • the choice of fields • the content of the data that goes into each field • the syntax of the data that goes into each field The rules are an excellent example of technical writing, precise but clear. For an example, see: http://www.cs.cornell.edu/Courses/cs430/2004fa/slides/AACR.pdf

  15. Example: Controlled Vocabulary Terms marked * can appear in other hierarchies Source: presentation by Diane Hillmann, 2004

  16. MARC Format The MARC format was developed in the late 1960s as a tagging scheme for exchanging catalog records on magnetic tape. It remains the standard way to represent such data. At present, MARC is steadily being converted (slowly) to modern computing formats, e.g., Unicode, XML.

  17. MARC: Monograph catalog record • Citation • Caroline R. Arms, editor, Campus strategies for libraries and electronic information. Bedford, MA: Digital Press, 1990.

  18. MARC fields • tagvalue • 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

  19. 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

  20. MARC Encoding tag: 260 subfield a: {Bedford, Mass.} : subfield b: Digital Press, subfield c: c1990. MARC encoding: &2600#abc#{Bedford, Mass.} :#Digital Press,#c1990.% [Definitely not a modern encoding!] Note that the content is designed to be part of a printed catalog record and is not in a convenient format for computer manipulation.

  21. Name authority files • An Authority File "brings together like items and differentiates among similar ones." • Caroline R. Arms or Caroline Ruth Arms? • Which William Phillips of Cardiff? • Mark Twain or Samuel Clemens? • Epithets: • of Cardiff • doctor • Dates: • 1832 - 1876 • flourished 1860 • circa 1832 - 1876

  22. Name authority: example LC Control Number: n 87870182 HEADING : Arms, Caroline R. (Caroline Ruth) 000 00907cz 2200205n 450 001 4383796 005 19890706143144.8 008 70909n|acannaab |a aaa c 010 __ |a n 87870182 035 __ |a (DLC)n 87870182 040 __ |a InU |c DLC |d DLC 100 10 |a Arms, Caroline R. |q (Caroline Ruth) 400 10 |w nna |a Arms, Caroline Ruth 400 10 |a Arms, C. R. |q (Caroline Ruth) 670 __ |a Arms, W.Y. Report on the performance problems of the RLIN computer system, 1982: |b t.p. (Caroline R. Arms) 670 __ |a LC data base, 8/24/87 |b (hdg.: Arms, Caroline Ruth; usage: Caroline R. Arms, C. R. Arms) 670 __ |a Campus networking strategies, 1988: |b CIP t.p. (Caroline Arms) 670 __ |a Phone call to pub., 2/10/88 |b (Caroline Ruth Arms; studied at Oxford) 670 __ |a Campus strategies for libraries and electronic information, c1990: |b CIP t.p. (Caroline Arms) data sheet (b. 10-24-45) 953 __ |a bz46 |b bd24

  23. Subject information Library of Congress Subject Headings Academic libraries--United States--Automation Hierarchical classification Library of Congress call number: Z675.U5C16 Dewey Decimal Classification: 027.7 Creation and maintenance of lists of subject headings and classifications is a never ending task.

  24. Online public access catalog (OPAC) • History: First stage • Library mounts its MARC records on a central computer • Provides a simple terminal interface and dedicated terminals • Boolean search -- fielded searching • [Most university libraries reached this stage about 1990] • History: Second stage • Library connects computer to a campus network and Internet • Converts card catalog records to MARC (retrospective conversion)

  25. Library information systems • When the catalog is online ... • Add other collections and services: • Secondary information (Inspec, Medline, Chemical Abstracts) • Reference works (dictionaries, encyclopedias) • Improve user interface • Add full text searching • Add web interface • Add gateway to off-campus information sources: • Scientific journals • Databases (census, genome)

  26. 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.

  27. Notes on MARC • 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?)

  28. Notes on MARC • 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 of million records at $100 -- $10 billion • A classic legacy system!

More Related