Subject languages part 2:
Structure
Structure of subject languages
• Alphabetical representation and classified
representation.
• Synthetic structure and enumerative structure.
• Parallel hierarchies and facets.
Examples of alphabetic representation
Architecture
Art
Biology
Chemistry
Engineering
Fine arts
Life sciences
Architecture
BT Fine arts
NT Landscape
architecture
Biology
BT Life sciences
NT Evolutionary
biology, molecular
biology
Example of classified representation
Arts and sciences
Fine arts
Visual art
Architecture
Landscape architecture
Music
Sciences
Life sciences
Biology
New York Times
information
architecture
Examples of synthetic structure
In 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. An
example from the 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.
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
Examples of parallel hierarchies
From the Eurovoc thesaurus, used to describe EU government
documents:
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
Examples of facets
In 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
Internal structure of subject languages
• Hierarchical relationships.
• Equivalence relationships.
• Associative relationships.
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?
Types of hierarchical relationships
Genus-species
Follow 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-part
Often 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!
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 division
People
(by family role)
mothers
fathers
children
(by occupation)
opera singers
information professionals
mushroom hunters
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.)
A better example
Paintings
paintings by representational
focus
Portraits
Landscape
paintings by style
Renaissance paintings
Impressionist paintings
paintings by materials used
Oil paintings
paintings by means of
support
Cave paintings
Murals
These might be separate facets
for a classification of paintings:
Representational focus
Style
Materials
Means of support
Trees
According to Kwasnik, a tree is a looser form
that shows a consistent principle of organization,
but does not have the strict rules of inheritance
and so forth that hierarchies have.
Example:
Grandparents
Parents
Children
Examples of subject languages
• Warburg Institute classification.
• Alcohol and Other Drugs thesaurus.
Assignment components
•
•
•
•
Introduction.
Classified representation.
Alphabetical representation.
Reflective essay.
Example: Garden decor
An excerpt of a classified structure for an “expressive gardening”
classification that includes “garden decor” as a concept:
Principles of garden expression
creativity
unity
Means of garden expression
plant selection
garden design
garden decor
Example: Garden decor
An excerpt of an alphabetical structure for an “expressive gardening”
classification that includes “garden decor” as a concept:
garden decor
broader term: means of garden expression
definition: non-plant materials that add visual interest and, potentially,
functionality(such as a place to sit) to the garden space. Benches, garden
sculpture, and windchimes are all elements of garden decor.
scope note: Documents that describe elements of garden decor, advise on their
purchase, and explain their use should all be indexed with this term. Documents
that describe the principles by which decor is selected and placed should be
indexed under the principle. Non-plant materials that are used to facilitate plant
growth or structure (such as arbors) are considered plant support, not decor.
Non-subject concepts
Don’t include document attributes that aren’t subjects, such as forms or genres
(blogs, articles, books, diaries...).
You are creating a representation of a subject that can be used to organize
documents; you are not describing the types of documents in which users might
be interested.
Include in your classification: terms for concepts that relate to gardening, such
as types of plants (grasses, cacti, shrubs).
Do not include in your classification: Document types that list such plants
(plant databases, seed catalogs). However, you might use your classification to
categorize a cactus database with the Cacti concept...
Sort like with like
Try to place like kinds of things together (processes, products,
people), not just things that have some thematic relation.
Remember, a hierarchy in its strict form takes one kind of thing
and goes from the most general category to the most specific.
this: Animals -> domesticated animals -> animals raised for food
-> pigs
this: Agricultural processes -> farming -> factory farming
this: Effects -> effects of farming practices -> effects on animals
-> overcrowding
not this: Animals -> pastures, pens, cages -> overcrowding
not this: Animals -> factory farming -> mercury poisoning
Levels of abstraction
Wrangling your concepts can be difficult when they are at different
levels of abstraction. You may need to generate intermediate levels
that weren’t explicit in your source documents.
Source concepts: meat eating, e.coli, cholesterol, sustainability
disadvantages of meat eating
health risks
health risks associated with meat eating
high cholesterol
health risks associated with industrial meat production
bacterial contamination
e.coli contamination
unsustainable practices
effects of industrial meat production
consumption of resources
pollution
Node labels or subfacet labels
Especially because your
classifications are small, many of you
may make use of labels that help
clarify the principles of division used
in your classified structure.
In most cases, you will not use these
terms to describe documents, and
they are not, strictly speaking, actual
concepts in your classification. You
don’t need to include them in your
alphabetical representation.
Example
Computers
<by form factor>
Desktop
Laptop
<by operating system>
MacOS
Linux
Windows
<by operating system> is just a
structural label. It’s not a
concept you’ll use to categorize
documents.
Your continuing mission
• Continue compiling a list of potential concepts for
your classification.
• Define an audience and purpose for your
classification, and use this, as well as your subject
knowledge, to more clearly define the scope of your
classification, its boundaries and its central and
peripheral areas.