Dewey Decimal Classification
An Introductory Outline

 

  1. Selecting the best possible classification scheme
    1. it must provide the ideal arrangement of all recorded knowledge
    2. its notation must be easy for classifiers to work with
    3. its principles and notation must be easy for end users to understand
    1. notion of an "ideal arrangement" is largely subjective
    2. the attributes a scheme must have in order to satisfy the above conditions are mutually contradictory:
    1. a principle of classifying that places like materials together
    2. provision for classification by several approaches; e.g., subject matter, form, function, time
    3. a set of main classes that are mutually exclusive
    4. infinite expandability and capacity for modification
    5. coherence, order, and comprehensiveness
    6. a system of notation that

      7. --is simple, definitive, and flexible, and

      --can readily be accommodated by computer programs which produce printed products

    7. usefulness as a searching and retrieval tool in an online catalog
    1. therefore, no classification scheme ever devised has had all of these attributes
    1. examples:
--Universal Decimal Classification and Ranganathan's colon classification both
      1. permit classification by several principles and have definitive systems
      2. but are difficult to learn and require complicated notation
--abridged editions of DDC are inadequate for large collections and lack flexibility
    1. next best thing consists of
--satisfying all three basic conditions insofar as it is possible, and

--chosing one of the three conditions to satisfy completely
    1. doesn't entirely succeed in this purpose due to its American/Western/ Christian emphasis
    1. this bias due to

      2. --Dewey's world view, and

      --the prevailing attitudes of Dewey's time

    2. each successive edition has modified this bias
    3. certain classes - the pure sciences, technology, and "Generalities" - suffer only the limitations inherent in any scheme attempting to cover all knowledge; predicting juman endeavor impossible
    1. despite a few practical problems, DDC doesn't ignore the other two conditions
    2. proof it's workable and practical:
    1. continually published and revised for 120 years
    2. used in more than 135 countries
    3. translated into over 30 languages
    4. in U.S., used in 95% of all public and school libraries, 25% of all academic libraries, and 20% of all special libraries (DDC, 20th ed., 1989)
  1. Structure and notation
    1. divided and subdivided on the decimal principle
    2. digits "0" through "9" used to represent topics and their subdivisions
000 Generalities
    1. Philosophy, parapsychology and occultism, psychology
    1. Religion
    1. Social sciences
    1. Language
    1. Natural sciences and mathematics
    1. Technology (Applied sciences)
    1. The arts. Fine and decorative arts.
    1. Literature
900 General geography, history and auxiliary disciplines
    1. digit "O" never represents a distinct subdivision of a topic
    2. example of 600 class:
    1. Medical sciences
    1. Engineering and applied operations
    1. Agriculture and related technologies
    1. Home economics and family living
    1. Management and auxiliary services
    1. Chemical engineering
    1. Manufacturing
    1. Manufacture for specific use
690 Buildings
    1. known as the "Second Summary" of the class
    1. the digits "1" through "9" divide the topic in uestion into 9 still narrower subtopics
    2. examples:
    1. Libraries for special subjects; one of the subdivisions of "610" above
641 Food sciences; subdivision of 640
    1. example: under 745.5 (Handicrafts) appears a list headed 741.51-745.58 (In specific materials)
    2. the DDC Schedules flag such lists with the symbol ">"
    3. such lists are called centered entries
    1. example:
    1. Old Testament
    1. Parts of Old Testament
    1. New Testament
226-228 Parts of New Testament
    1. in other words, if 220 represents the whole Bible, then the third digit should represent either the Old or New Testament, and the fourth digit should represent some portion of either
    1. rather, DDC has bent its rules slightly in the name of common sense; going strictly by the rules would have involved wasting seven of the nine digits in the third position
    2. the only other alternative would have been to provide no numbers designating the entire Old and New Testaments; which would have been even less desirable
    1. a Dewey number is made up entirely of arabic numerals
    2. if a number exceeds three digits, a decimal point separates the third and fourth
    3. regarding the amount of digits: minimum of three, no upper limit
    4. numbers denoting broad, general topics will have one or two zeros following the significant digit(s)
    5. longer numbers denote more specific topics than shorter ones
    6. example of progression from a number at the most general level to a very specific one:
    1. Social sciences
    1. Economics
    1. Labor economics
      1. Labor force and market
    1. Labor force
331.118 Labor productivity
  1. Auxiliary tables for number expansion
    1. under no circumstances may numbers from the tables be used by themselves
    2. you may add the numbers from Tables 1 and 2 to almost any Dewey number, but only according to very precise rules of application
    3. you may only use tables 3-7 when the schedules explicitly instruct you to
Table 1: Standard subdivisions (point of view, form, etc.) - may be used as required with any number from the schedules in accordance with uniformly applied instructions

Table 2: Areas - Geographical subdivision, to be used as required with any number from the schedules, either directly when so quoted or by the interposition of "09"

Specific directives: added directly to area codes - will supersede the general instruction to interpose the tag "09"

Table 3: Subdivisions for individual literatures (the literary forms poetry, drama, fiction, etc.) - to be used as directed with the base numbers of individual literatures in the 800 class

Table 4: Subdivisions of individual languages (alphabets, spelling, grammar, etymology, etc.) - may be used as required with base numbers for individual languages I the 400 class

Table 5: Racial, ethnic, national groups - to be used oly as directed in the main schedules

Table 6: Languages - to be used only as directed in the main schedules

Table 7: Groups of Persons - to be used only as directed in the main schedules
  1. The relative index
    1. each denotes an approach from a different point of view
    2. you may then choose the number which best reresents the point of view of the item yu are cataloging
    3. example: dogs may be thought of as
    1. mammals
    2. pets
    3. guides for the blind
    4. experimental animals for science
    1. rather, it uses direct and specific entries
    2. example: "Ice"
    1. in 19th edition of DDC was a long hierarchical display of 36 subordinate terms
    2. 20th edition uses terms - all formerly subsumed uder the broad heading of "Ice" - such as "ice cream," "ice hockey," and "ice storms"
  1. Annual for the Use of the Dewey Decimal Classification
    1. the latter consists chiefly of comparisons between different classification numbers that appear to have the same meaning
    2. not all possible comparisons listed
    3. those chosen not only well developed, but illustrate the need to understand the connotative meaning of the classes compared
    4. example: difference between 152 - (Psychology of) Sensory perception, movement, emotions, physiological drives) and 612.8 - (Physiology of) Nervous functions
152 > works that emphasize awareness, sensation, intentions, meanings, and actions as experienced by the individual or observed and described without reference to the physics or chemistry of the nervous system; e.g., seeing colors, feeling anger.

612.8 > works that emphasize the physical and chemicl mechanisms and pathways of sensations, emotions, movements; e.g., studies using electrodes to determine what parts of the brain process different kinds of stimuli.

*class comprehensive works in 152; if in doubt, prefer 612.8
  1. Faceting
    1. prior to 20th edition, often called "Divide-like" directives
    2. 3 forms:
    1. Add to base number (number you have built up to that point) notation (digit or range of digits) from (a specific point in the Tables or elsewhere in the Schedules)

      2. 133.129: Specific haunted places

      Add to base number 133.129 notation from Tablb2, e.g., the Tower of London 133.1294215

      The instruction is telling you to find the string of digits from Table 2 which denotes the place your number is to represent and add those digits to 133.129.

    2. Add (further modifying digits) as instructed under (a specified number from elsewhere in the Schdules)

      3. 546.381: Lithium*

      *(Footnote) Add as instructed under 546.

      At 546, "Inorganic chemistry," there appears what looks like a minitable. There are many such tables throughout DDC. They demonstrate, for a whole class of numbers, how to modify each specific number within that class. These tables are used when modifications of a broad topic are also applicable, to all components of that topic. In this case, "546: Inorganic chemistry," is the broad topic of which "546.381: Lithium," an alkali metal, is one of the components.

    3. Add to base number (the number you have built up to this point) notation 001-999 (i.e., any complete number from the scheme).
026: Libraries

220.8: Non-religious subjects treated in the Bible

610: Medicine

026.61: Medical libraries'

220.861: Biblical discussion of medicine
  1. Use of mnemonics
    1. faceting
    2. use of a certain number to represent related subjects
    1. use of "6" to represent things Spanish
    2. 460: Spanish language
860: Spanish literature

946: Spain
    1. rather than a table or set of instructions providing directions, DDC's developers have agreed to use such digits whenever possible
    2. exception: these is a systematic use of mnemonics within both the 400 and 800 classes
  1. Problems in use of DDC
    1. examples
    1. Christianity takes up range 210-289 while all other religions are crammed into the 290s
    2. in classes 400 and 800, English, French, German, Italian, Spanish, Greek, an Latin each receive their own digit in the 2nd position
--all other languages/literature are squeezed into the 490s and 890s

--e.g., 495.1: Chinese language; 895.1 Chinese literature
    1. from a conceptual viewpoint (in that any Dewey number is infinitely expandable) this bias may seem artificial
    1. however, from a practical standpoint, numers must be much longer to achieve the same level of specificity
    2. libraries having a policy of taking every Dewey number out only to a set number of digits will not be able to define certain topics as sharply
    1. often difficult to expand any section of the scheme to accommodate new subjects
    2. new classes cannot be assigned arbitrarily by changing the meaning of former classes
    1. if this were allowed, the scheme would lose its integrity
    2. where unassigned numbers are unavailable, new topics must be accommodated through the extension of existing numbers
    3. exception: in 20th edition, a new "Music" schedule provided for 780s
    1. example: 338.45613621109771334 (Production efficiency of those employed in hospital services in Lake County, Ohio)
    2. one solution: allow a maximum of three or four characters per line, placing line breaks between logical units, even if that results in only one or two digits per line