S.R. Ranganathan was an influential Indian librarian and library scientist who developed the Five Laws of Library Science, which serve as the foundation of modern library practice. In addition to these laws, Ranganathan also proposed the concept of “modes of formation of subjects.” This concept was further extended and elaborated upon by V.S. Neelameghan, a noted librarian and scholar. The modes of formation of subjects offer a systematic approach to organizing knowledge within library classification systems.

Ranganathan initially identified five modes of formation of subjects, and Neelameghan expanded these to nine. The modes of formation provide a way to categorize and structure subject areas based on the relationships between topics. Here’s a brief explanation of both Ranganathan’s original five modes and Neelameghan’s extended nine modes:

Ranganathan’s Five Modes of Formation of Subjects:

1. Synthetic Mode: This mode involves the combination of different subjects to create a new, comprehensive subject. For example, the subject “Environmental Sociology” combines elements of both environmental studies and sociology.
2. Analytic Mode: In this mode, a subject is divided into its constituent parts for more detailed examination. For instance, “Literature” could be analyzed into subtopics such as “Poetry,” “Prose,” and “Drama.”
3. Sythetic-Analytic Mode: This mode combines elements of the first two modes. It involves the creation of comprehensive subjects by merging smaller subjects and then analyzing those subjects further. An example would be “History of Art,” which synthesizes the broader category of “Art” and then breaks it down analytically into various historical periods and styles.
4. Divisive Mode: This mode involves dividing a subject into its subcategories. For example, the subject “Botany” could be divided into subcategories like “Plant Anatomy,” “Plant Taxonomy,” and “Plant Physiology.”
5. Collocative Mode: Collocation refers to the arrangement of related subjects in close proximity within a classification system. This mode ensures that subjects that are closely related or frequently used together are located near each other on the shelves or within the catalog.

Neelameghan’s Extended Nine Modes of Formation of Subjects: 6. Semicollocative Mode: This mode is similar to the collocative mode, but it allows for some degree of dispersion of related subjects to improve browsing. Subjects that are closely related are still placed near each other, but not as strictly as in the collocative mode.

7. Stenochronous Mode: This mode involves arranging subjects according to their historical development or chronological sequence. It is particularly relevant for subjects that have evolved over time, such as “Technology” or “Science.”
8. Enumerative Mode: In this mode, subjects are enumerated based on the lists of their constituent elements. It involves creating lists of specific instances or examples within a broader subject area.
9. Chronocollocative Mode: This mode combines aspects of chronological and collocative modes. Subjects are grouped based on their historical development, and related subjects are also placed in proximity for ease of access.

These modes of formation of subjects provide a structured framework for organizing and presenting information in libraries and classification systems. They help librarians and information professionals create meaningful connections between subjects, making it easier for users to navigate and access relevant information.