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: Bank deposit insurance—United States The number is built with 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 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:

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:

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 Desktop Laptop MacOS Linux Windows 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.