inf 384 c, spring 2009 subject languages category structures to represent topics
TRANSCRIPT
INF 384 C, Spring 2009
Subject Languages
Category structures to represent topics
INF 384 C, Spring 2009
Outline
• Why? What are the goals of subject languages?
• What? What do subject languages look like?
• How? On what basis are subject languages created?
INF 384 C, Spring 2009
Goals of subject languages
Ranganathan: To provide a helpful sequence of documents, so that:• Readers discover topics that may be useful. • Books can display their potential to readers.
Svenonius: To improve collocation in retrieval; to navigate the bibliographic universe; to represent knowledge (as opposed to information).
INF 384 C, Spring 2009
Components of subject languages
Subject languages contain concepts represented as terms.
The concept of “pH of water components of soil, and the effects of this pH on the soil’s use in supporting plant life,” may be represented as the term “soil acidity.”
INF 384 C, Spring 2009
Structure of subject languages
• Alphabetical representation and classified representation.
• Synthetic structure and enumerative structure.
• Parallel hierarchies and facets.
INF 384 C, Spring 2009
Examples of alphabetic representation
ArchitectureArtBiologyChemistryEngineeringFine artsLife sciences
Architecture
BT Fine arts
NT Landscape architecture
Biology
BT Life sciences
NT Evolutionary biology, molecular biology
INF 384 C, Spring 2009
Example of classified representation
Arts and sciences
Fine arts
Visual art
Architecture
Landscape architecture
Music
Sciences
Life sciences
Biology
New York Times information architecture
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Examples of synthetic structureIn Ranganathan’s Colon Classification, subjects are constructed by arranging concepts from the facets Personality, Matter, Energy, Space, and Time (PMEST).
In the Dewey Decimal Classification, geographic information is appended to a class name by means of standard tables. Topical example from Dewey blog:
368.85400973 Bank deposit insurance—United States
The number is built with 368.854 plus 0 (extra 0 for standard subdivisions as instructed in the add table under 368.1–368.8 Specific kinds of insurance) plus T1—09 Geographic treatment plus T2—73 United States.
INF 384 C, Spring 2009
Example of enumerative structure
Warburg Institute classification: Image hierarchy main classes
Primitive Art, Oriental Art, Classical Archaeology, Classical Topography, Classical Iconography, Numismatics, Greek Art, Roman Art, History of Art, Sources of the History of Art, Art Interpretation, Aesthetics, Topography, Iconography, Survival Of Ancient Art, Early Christian & Byzantine Art, Illuminated Manuscripts, Italian Art, Spanish Art, French Art, Flemish & Dutch Art, British Art, German Art, Scandinavian Art, Applied Arts, Art Collecting, 19th & 20th Century Art
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Examples of parallel hierarchies
04 POLITICS
0406 political framework
0411 political party
0416 electoral procedure and voting
0421 parliament
0426 parliamentary proceedings
0431 politics and public safety
0436 executive power and public service
08 INTERNATIONAL RELATIONS 0806 international affairs 0811 cooperation policy 0816 international balance 0821 defence
10 EUROPEAN COMMUNITIES 1006 Community institutions and
European civil service 1011 European Union law 1016 European construction 1021 Community finance
From the Eurovoc thesaurus, used to describe EU government documents:
INF 384 C, Spring 2009
Examples of facetsIn the Bliss Bibliographic Classification (BBC v.2), the Human Biology and Medicine field is organized into the following facets:
• Types of persons
• Parts and systems of the person
• Processes in the person
• Actions on the person
• Agents of actions
A document whose subject is nursing for children with cancer would be described as:
(Type of person) Paediatrics - (Processes) - Pathological - Cancer - (Actions on) Nursing
Example from Bliss Classification Association: http://www.blissclassification.org.uk/bchist.htm
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Internal structure of subject languages
• Hierarchical relationships.
• Equivalence relationships.
• Associative relationships.
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Scope of hierarchical relationships
Universal hierarchies (mammal -> dog). Always true!
Perspective hierarchies (pet -> dog, or work animal -> dog, or food -> dog). Only true under a certain point of view or certain conditions.
Can a subject language ever attain universality?
INF 384 C, Spring 2009
Types of hierarchical relationshipsGenus-speciesFollow the all-some rule—X is a type of Y if all X’s are Y’s but only some Y’s are X’s: all dogs are mammals but not all mammals are dogs. All the sibling concepts should follow the same principle of division and be mutually exclusive, or multiple principles of division should be elucidated through the structure.
Whole-partOften treated as associative relationships in subject languages. A few exceptions:
• Systems and organs of the body• Geographical locations• Disciplines and subdisciplines• Hierarchical social structures
Instance Not types but instances: they involve proper names (Seas: Baltic Sea, Mediterranean Sea). Not part of your subject language!
INF 384 C, Spring 2009
Examples of genus-species relationships
Single principle of division
Programming languages
Declarative languages
Functional languages
Imperative languages
Object-oriented languages
Procedural languages
Multiple principles of divisionPeople
(by family role)mothersfatherschildren
(by occupation)opera singersinformation professionalsmushroom hunters
INF 384 C, Spring 2009
A negative example
Unclear principles of division
Paintings
Portraits
Renaissance paintings
Oil paintings
Cave paintings
Impressionist paintings
Landscapes
Murals
These concepts do indeed describe types of paintings, but they represent multiple perspectives on painting.
Mixing principles of division like this makes the structure difficult to understand and browse. (If we did need to place an item in one location, it would be impossible, as well.)
INF 384 C, Spring 2009
Examples of subject languages
• Warburg Institute classification.
• Alcohol and Other Drugs thesaurus.
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Defining the scope of subject languages
What marks the extent of a subject?
Should a classification of “information organization” as a subject include information retrieval? Should it include philosophy of language? Should it include critical theory?
How does one make such decisions?
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Rationale for including concepts in subject languages
• Literary warrant.
• Use warrant.
• Structural warrant.
• Cultural warrant.
• Others?
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Example of structural warrant
<railways by means of propulsion>
<railways by power source>
<stationary traction source>
atmospheric railway
cable haulage railway
counterbalanced railway
water balance railway
rope haulage railway
gravity railway
<traction source moving with train>
animal powered railway
horse railway
locomotive railway
<self-propelled using externally supplied power>
electric railway
From the MDA Railway Object Name thesaurus
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Basic design process for subject languages
• Define the subject. How? Do research. Define the context. Think.
• Determine the concepts to include. How? Do research. Consider the context. Think.
• Structure the concepts with hierarchical and associative relationships. Add, delete, broaden, or narrow concepts to balance the structure.
• Arrange the concepts at each hierarchical branch.
INF 384 C, Spring 2009
Your current mission
• Research the subject.
• Determine a purpose and audience for your classification.
• Use the purpose and audience to define and scope the subject.
• Collect concepts for potential inclusion.