Ranganathan: Faceted Classification


Shiyali Ramamrita Ranganathan (1872-1972) is one of the most influential figures in the field of library and information sciences. This paper argues that Ranganathan is a thinker ahead of his time. The fact that his ideas and his Colon Classification scheme are not well received and practised can probably be attributed to his vision being too advanced for his contemporary world of technology. Considering the progress that has been made since his times, Ranganathan’s ideas deserve another investigation. Upon comparing the nature of his classification scheme with the various technologies like relational databases, online retrieval systems, or the World Wide Web, it is quite evident that Ranganathan’s ideas of classification are more applicable now than before.

The following is a brief description of each individual page in this website:

Evolution of Classification

Describes the traditional, enumerative classification schemes and the disadvantages of such schemes, which call for a new way of organizing knowledge.

Faceted Classifcation

Provides a more detailed account of the mechanisms of faceted classification schemes.

Colon Classification

Gives a background of Ranganathan’s classification scheme.

Database Design

Parallels the development of classification schemes to database data model’s evolution. Suggests that perhaps the Colon Classification and other analytico-synthetic schemes are inherently more compatible with the construction principles of relational databases. More on database design in this platform.

Online Retrieval Systems

Discusses why the Colon Classification can be useful in designing a more effective online retrieval system from a user’s point of view. More on Online Retrieval Systems in this platform.

Internet Classification

Describes how Ranganathan’s ideas of classification can be applied to the web. More on Internet Classification in this platform.


Lists the sources consulted.


Nature of Traditional Classification Schemes

Many of the traditional classification schemes like the Library of Congress Classification (LCC) and Dewey Decimal Classification (DDC) are considered “enumerative”, meaning that they list in their schedules the notations for all the possible subjects in the world of knowledge. The classifier’s job is to pick one of the ready-made numbers for the particular information package. In other words, the notations are “precoordinated”. Another type of classification schemes is the “hierarchical” classification. The divisions and subdivisions are based on a more philosophical convention of classifiying the particular subject.

Disadvantages of Enumerative Schemes

Enumerative schemes were sufficient in the early days because there was not a great number of materials to be classified. Knowledge at that time is in a “static continuium” (Wali and Koul 1972, 31). However, one of major drawbacks is that there is “a rigidly specified network of pathways leading to rigidly grouped collections of items” (Vickery 1966, 30). The classifier has to “fit each book into existing pigeon-holes” (Glassel 1998).

Classifcation schemes like the DDC or the LCC are limited in their ways of bringing out the full spectrum of subjects in an information package. LCC in particular is deficient in this respect. LCC often uses Cutter extensions to further describes the content of the item. However, since only two Cutter numbers are allowed, the resulting notation cannot express many important aspects of the item.

Therefore, the need arises to investigate another way of organizing knowledge.



Faceted classification is also called analytico-synthetic, named after the two main processes involved in the composition of a call number. The two processes are:

Breaking down each subject into its basic concepts.

Combining the relevant units and concepts to describe the subject matter of the information package in hand.

A facet is a “clearly definied, mutually exclusive, and collectively exhaustive aspects, properties or characteristics of a class or specific subject” (Maple 1997)


Let us consider the construction of a notation using the Ranganathan’s Colon Classification.

Suppose we have a book that is about “research in the cure of tuberculosis of lungs by x-ray conducted in India in 1950” (Glassel, 1998)

The call number will be as follows,


The notations represent


It is amazing how the notation covers all the significant aspects of the subject of the item. Such a classification scheme is considered to be “hospitable” to all sorts of complex topics. It is therefore a “dynamic” scheme.


The ease and flexibility of formulating composite subjects

The classifier, using the traditional enumerative schemes, is often compelled to choose a number to fit the information package in hand. Many important aspects of the subject of the item have to be omitted because the schedules do not list them. An expressive notation, therefore, cannot be built. To bring out these aspects, one has to rely on other tools like subject headings.

In addition, if a book has an interdisciplinary approach, for instance,

However, since only the basic concepts are given in the schedules of a faceted classification, the classifier can combine at will any concept with another to produce a tailored call number for the specific item. An infinite number of combinations can result.

The ease of accomodating new concepts

When a new subject is needed, a classifier using an enumerative scheme will have to wait until the scheme provides a term for that particular subject. On the other hand, since we start with the basic concepts and build towards our topic, it is much easier to combine already-existing terms to form a new subject.


There are many advantages to having a unique collection of facets for each class of knowledge. Because the facets for one class are compiled independently of another class, this ensures that the terms chosen are specific to that class and are the current terms used by people in the field.

The specificity that can be expressed in the notation

The example given above is illustrative of the details that can be expressed by a notation synthesized using a faceted classification scheme.


Idea of a Faceted Scheme

Although Ranganathan was not the inventor of facet analysis, he is credited as the first to “systematize and formalize the theory” (Chan 1994, 390). It is said that Ranganthan’s idea of a faceted classification scheme is inspired by a Lego-type toy set. Seeing that the salesperson can build different toys just by combining the same pieces in a different way, he builds his classification scheme by this analogy (Garfield 1984, 40).

Components of Ranganathan’s Scheme

The Colon Classification, just as other classification schemes, starts with a number of main classes (42), which represent the fields of knowledge.

Each class is then anaylzed and broken down into its basic elements, grouped together by common attributes, called facets.

Upon examining all the facets, Ranganthan notices that there are five main groups into which the facets fall, and he calls these the fundamental categories, represented by the mnemonic PMEST in an order of decreasing concreteness.


-can be understood as the primary facet.
-the most prominent attribute


-physical material






-time period

There are also facets that are common to all the classes. These are called common isolates. Examples include form and language.

The same facet can be used more than once.

Notations, such as numbers and letters, are used to represent the facets, while punctuation marks are used to indicate the nature and type of the following facets.

The classifier’s job, therefore, is to combine the available terms that are appropriate in describing the information package in hand.


Chan, Lois Mai. Cataloging and Classification: An Introduction. 2nd ed. New York: McGraw-Hill, 1994.

Ellis, David, and Ana Vasconcelos. “Ranganathan and the Net: Using Facet Analysis to Search and Organise World Wide Web.” Aslib Proceedings: New Information Perspectives 51, no. 1 (1999): 3-10.

Foskett, A. C. The Subject Approach to Information. 4th ed. London: Clive Bingley, 1982.

Foskett, D. J. “Ranganathan and ‘User-Friendliness’.” Libri 42, no. 3 (1992): 235-241.

Garfield, Eugene. “A Tribute to S. R. Ranganathan, the Father of Indican Library Science. Part 1. Life and Works.” In Essays of an Information Scientist 7 (1984): 37-44.

Glassel, Aimee. “Was Ranganthan a Yahoo!?” End User’s Corner (17 March, 2000).

Godert, Winfried. “Facet Classification in Online Retrieval.” International Classification 18, no. 2 (1991): 98-109.

Kwasnik, Barbara H. “The Role of Classification in Knowledge Representation and Discovery.” Library Trends 48, no. 1 (1999): 22-47.

Maple, Amanda. “Faceted Access: A Review of the Literature.” (16 March, 2000)

Neelameghan, A. “Application of Ranganathan’s General Theory of Knowledge Classification in Designing Specialized Databases.” Libri 42, no. 3 (1992): 202-226.

Pollitt, Steven. Interactive Information Retrieval Based on Faceted Classification Using Views (16 March, 2000)

Ranganathan, S. R. Elements of Library Classification. Bombay: Asia Publishing House, 1962.

Vickery, B. C. Faceted Classification Schemes. Rutgers Series on Systems for the Intellectual Organization of Information, ed. Susan Artandi, v. 5. New Brunswick, NJ: Rutgers University Press, 1966.

Wali, M. L., and R. K. Koul. “Development of Notation in Freely Faceted Classification: A Case Study.” Herald in Library Science 11, no. 1 (1972): 30-43.