The concept of "subject" in classification theory, particularly as established by S.R. Ranganathan, is divided into distinct types based on their components and complexity. Understanding these types—Basic, Compound, and Complex (or Intricate) subjects—is crucial for subject analysis and classification.
1. Basic Subject (BS) / Vital Subject
A Basic Subject (BS) is a subject that is enumerated in the schedule of basic subjects. It serves as a foundational concept in classification.
Key Attributes:
- It cannot be expressed as a Compound Subject of any existing Basic Subject. It is, in essence, a subject without any isolate idea as a component.
- It is evolved through one full cycle of the spiral of scientific method.
- Basic Subjects exhibit different modes of formation of subjects.
- They call for schedules of special Personality, Matter, and Energy isolates.
- Indicators of a Basic Subject having specialization (academic and/or professional segmentation) include the existence of professional societies, degree courses, periodical publications, and whole books on the subject.
- Examples include mathematics, economics, and law. Other examples mentioned are physics, thermodynamics, Marxian economics, Homeopathy medicine, music, and library science.
Further Species of Basic Subjects
Basic Subjects (BS) can be broadly divided into Main Basic Subjects and Non-Main Basic Subjects, with further species identified based on their modes of formation:
| Type of Basic Subject | Category | Examples |
|---|---|---|
| Traditional | Main Basic Subject | Law, Physics |
| Newly emerging | Main Basic Subject | Library & Information Science |
| Fused | Main Basic Subject | Biotechnology |
| Distilled | Main Basic Subject | Research methodology |
| Subject bundles | Main Basic Subject | Ocean sciences |
| Agglomerates | Main Basic Subject | Social sciences |
| Canonical classes | Non-Main Basic Subject | Algebra, Geometry |
| System constituents | Non-Main Basic Subject | Marxian economy |
| Environment constituents | Non-Main Basic Subject | Desert farming |
| Special constituents | Non-Main Basic Subject | Gerontology |
2. Compound Subject (CdS)
A Compound Subject (CdS) is a subject having a basic subject (basic facet) and one or more isolate ideas or concepts (isolate facet) as components. Compound subjects can be considered basic subjects with subdivisions or additional facets.
Key Attributes:
- The components of a compound subject constitute manifestations of one or more of the Five Fundamental Categories (PMEST): Personality [P], Matter [M], Energy [E], Space [S], and Time [T].
- An elaborate definition states that if a document describes only a part or portion of an entity's personality, or provides a description of one or some attributes possessed by entities, and/or actions on it by other entities, in a particular space and time context, the subject is deemed a compound subject.
- Compound subjects are virtually infinite in number.
- Examples include:
- "Mining of gold".
- "Chemistry of gold".
- "Biblical study of animals".
- "Botanical study of flows".
- "Treatment of cancer in Ayurvedic System of Medicine".
- "Velocity of light," "transport economics," "guitar music," "law of marriage," and "libraries in India".
3. Complex Subject (CxS) / Intricate Subject
A Complex Subject (CxS) (also referred to as an Intricate Subject) is a subject formed by a combination of two or more subjects—basic or compound.
Key Attributes:
- The combination describes their interrelationship, comparison, influence, etc..
- The formation of Complex Subjects is a result of Loose Assemblage of Kind-1 (Inter-subject phase relation), where two or more simple or compound subjects are studied in mutual relationship, such as General, Bias, Comparison, Difference, and Influencing relations.
- Examples include:
- "Physics compared to Chemistry".
- "Psychology for Doctors".
- "General relation between political science and economics".
- "Statistics for librarians".
- "Influence of geography on history".
- "Mathematics for engineers," "geophysics," "medical geography," or "comparative physiology".
These three types of subjects are analogous to chemical substances in the universe of knowledge.