INLS 150 Session 6

February 14, 2002

Cristina PattuelliSchool of Information & Library Science

University of North Carolina at Chapel Hill

Classification Puzzle

• Duck-billed platypus?• Water mole?• Egg-laying mammal?• Ornithorhynchus

paradoxus?• Platypus anatinus?• Ornithorhynchus

anatinus?Platypus plate. Reproduced from Bilderbuch fur Kinder: enthaltend eine

angenehme Sammlung von Thieren, Planzen, Blumen, Fruchten … by J.F. Bertuch (Weimar, Germany: im Verlage des Landes-Industrie-Comptoirs, 1798–

1830)

Classification

• Natural human learning activity

• Scientific/Bibliographic

Classification History

• Aristotle - Classical Theory of Categories – ten categories:– things are categorized together based on

what they have in common (properties)

– Clear boundaries, hierarchy mirroring the actual world

– Unchallenged until mid-19th c.

http://www.uh.edu/~cfreelan/courses/categories.html

Cracks in Classical Theory

• Wittgenstein, 1953, family resemblances

• Zadeh, 1965, fuzzy set theory

• Lonsbury, 1965, family kinship

• Rosch, 1973-early 1980’s, prototype theory– Ad hoc categories

Classification

• Multitude of uses:– Supermarkets’ shelf arrangement– Knowledge bases for expert systems– For data structure in business (organizational)

archives and knowledge repositories– Design of menus for interactive searching– Libraries’ stack arrangement (order)– Etc…

Bibliographic Tradition

Two methods for arranging materials:Alphabetical catalog (Subject Headings)

Classified catalog

Classification Schemes Typology 1

• Universal schemes

– Dewey Decimal Classification (DDC)

– Universal Decimal Classification (UDC)

– Library of Congress Classification (LCC)

Traugott Koch: http://www.lub.lu.se/desire/radar/reports/D3.2.3/class_v10.html

Began to be developed in North America during the 19th century

Classification Schemes Typology 2

• National general schemese.g., Governments maintain official

classifications of occupations and industries

Traugott Koch: http://www.lub.lu.se/desire/radar/reports/D3.2.3/class_v10.html

Classification Schemes Typology 3

• Subject specific schemes– National Library of Medicine (NML)

– Engineering Information (Ei)

– ACM Computing Classification System (CCS)

– Mathematics Subject Classification (MSC)

Traugott Koch: http://www.lub.lu.se/desire/radar/reports/D3.2.3/class_v10.html

Home-grown Schemes

• For particular services– Yahoo! search service

Traugott Koch: http://www.lub.lu.se/desire/radar/reports/D3.2.3/class_v10.html

Callimachus’ Classification10 πινάκης (pinakes)

• Epic, and other non dramatic poetry

• Drama

• Law

• Philosophy

• History

• Oratory

• Medicine

• Mathematical science

• Natural Science

• Miscellanea

Classified Catalog

• Related classes and categories• Hierarchical approach • Logical sequence from general to

specific• Notations facilitate creation of

hierarchical subject trees

Bibliographic Classification Scheme

• Component parts:– Schedule (e.g., division in classes, facets)– Notation (numbers and/or letters)– Index (list of related terms for accessing the

schedule)

Bibliographic Classification

• Two approaches:• Enumerative (assign a notation to every

concept in the system)• Faceted (like faces of a diamond)

– Facets = various subparts of the whole classification notation – synthetic approach

Classification Concepts

• Broad vs. Close

• Broad: only main classes and few subdivisions

• Close: all the detailed subdivisions available– Factors: collection’s size

Major Classification Schemes

• 1. DDC Dewey Decimal Classification

• 2. LCC Library of Congress Classification

• 3. UDC Universal Decimal Classification

• 4. CC Colon Classification

Dewey Decimal Classification (DDC)

1876 – Melvil Dewey

• Knowledge organization tool

• Provide access to libraries’ collections

• Also browsing mechanism for resources on the web

• The most widely used classification system in the world

DDC Structure

• Hierarchical Structure• Enumerative (list of categories one by one)• World of Knowledge divided in 10 main classes

(Classes represent disciplines or field of studies) - from 000 to 900 -

• Each class further divided into 10 divisions• Each division into 10 sections

– 999 classes in total

• Relative index

DDC Concepts

• Arranged by discipline

• Any specific topic can appear in any number of disciplines– e.g., a work on ‘FAMILIES” can be classed

in a number of different disciplines. Depending on its emphasis

DDC Family

• 173 Ethics of family relationships• 241.63 Christian family ethics• 296.4 Religious family rites, celebrations• 304.666 Family planning• 306.8 Marriage and family• 616.89156 Family psychotherapy• 796 Sports for family• 929.2 Family histories

A. Taylor, 2000

DDC Notation

• Decimal notation in Arabic numerals– much simpler than previous solutions (roman numerals,

etc.)

• Number Building:• 500 – Natural sciences and mathematics

– 510 Mathematics, 520 Astronomy, 530 Physics• 530 –general works on physics, 531 classical mechanics, 532

fluid mechanics, 533 gas mechanics..

• A decimal point after each 3 digits.

How DDC Works

• First, by knowledge area – classes

• Then, faceting arrangement – there are characteristics that should be applicable to all topics (belonging to a place, being in the form of a periodical, etc.)

– Standard Tables (e.g., for geographical areas, time periods, persons, forms of materials)

• E.g., US always 73 – has to be appended by means of 09 (facet indicator)

How DDC Works

– E.g. a dictionary of mathematical terms:– First, the number for mathematics

– Then, standard subdivision for ‘dictionary’

– Literature is an exception:• Always first by language used by author –list--

• Then, by form (e.g., poetry, novel, drama) –tables--

• And/or by period when the author wrote –tables--

How DDC Works

• Well-defined categories

• Well-developed hierarchies

• Rich network of relationships among topics

• Great detail of specificity

• Relative location vs. Fixed location

• Open Stacks – Browsing facility

How DDC Works

• When more than a topic/subject, choose the more general

• Borderline cases:– Consider the purpose of the creator(s)– Consider use of the item in the collection

DDC

• Integrity of numbers vs. Extensibility• Keeping pace with knowledge• Three areas completely remodeled:

– 350-354 Public Administration, 370 Education– 560-59 Life sciences

• Recent revisions:– Knowledge, systems and data processing

• 005 (computer)

DDC

21st edition – Update

New classes • Area of computers and computer networking

– 004.36 Client-server computing

– 004.678 Internet

– 005.118 Visual programming

– 006.32 Neural nets

– Etc…

DDC

21st edition – Revisions

• Extension of existing classes• Subdivisions:

– Operating system

– User interface

– Mode of processing

– Etc…

• 22nd edition - 2003

DDC Limitations

• Western knowledge oriented• American and Christian bias• 21st ed. Revised and expanded:

– 296 Judaism – 297 Islam– Revision for geographic area numbers:

• E.g. Soviet Union

Library of Congress Classification (LCC)

• 1897 – Herbert Putnam• LC’s own classification system• Mixed notation

– One or two letters for main classes +– Ordinal (whole) numbers +– One or more cutters +– Date at the end

• More economical notation

LCC

• For a library’s huge collection of books– too detailed and complex for small libraries

• Adopted by research and university libraries throughout the world

Universal Decimal Classification

• 1885 - Paul Otlet and Henri la Fontaine (Belgian lawyers)

• Institute Internationale de Bibliographie – The Document Movement (provide access to all

information in all formats)

Universal Decimal Classification

• Expansion of DDC (with Dewey’s permission)

• Arabic numbers + symbols for long and expressive notations

• Appropriate for specialist libraries and collections

• Adopted by International Organization for Standardization (ISO)

Colon Classification

• S.R. Ranganathan – early 1930s

• Faceted classification

• Classification based on subject’s uses and relations

• Notation– numbers divided by : (facet indicator)

Colon Classification

• Analytico-synthetic classification

• Facets first, then class numbers constructed by synthesis

Dewey Decimal Classification

• Dewey Decimal Classification – http://www.oclc.org/dewey/about/ddc_21_sum

maries.htm• Main Class 300 – Social Sciences

• The 1000 Sections 302 – Social Interaction

• Detailed Hierarchy for 320.2 – Communication

Library of Congress Classification

• Library of Congress Classification– http://www.loc.gov/catdir/cpso/lcco/lcco.html

• Main Class P – Language and Literature

• Subclass P – Philology, Linguistics

• P99-99.4 – Semiotics

Bibliographic Classification Schemes Online

• BULB LINK (DDC)http://link.bubl.ac.uk/ISC2

• CyberDewey (DDC) http://www.anthus.com/CyberDewey/CyberDewey.html

• CyberStacks (LLC)http://www.public.iastate.edu/~CYBERSTACKS/CTW.htm

Home-grown Schemes

• Yahoo!• Today

• Yesterday – http://web.archive.org/web/19961017235908/ht

tp://www2.yahoo.com/

Online Classification Advantages

• Improve retrieval capabilities - ?

• Improve navigation - ?

• Provide browsing facilities - ?

• Is a mechanism to switch b/w languages - ?

Pros

• Browsing a directory-type structure is user friendly

• Broadening and narrowing a search (hierarchy subject tree)

• Overview of the scope of a service• Look for related items not previously identified as

relevant - serendipity• Interoperability on agreed classification schemes• Etc…

Pros

• On the web you can assign more than one classification number to a resource and keep it virtually in several access locations at once.

• Not possible with physical resource

Cons

• Logical division of materials. Split up collection of related materials

• Not always logical subdivision of classes

• Delay in updating according with new areas of interest

Personal Experience

• What is your favorite?

• What do you think about…..