Susan Kelsch

407A Cataloging and Classification I, Summer II term

August 5, 2003

Ranganathan’s Colon Classification in 1500 Words or Less

A brief history of Colon Classification

Dr. Shiyali Ramamrita Ranganathan, who lived from 1892 until 1972, was a renowned thinker and innovator in the world of library and information science. He introduced one of his greatest contributions to the field, the Colon Classification scheme, in 1933. This was published in two slim volumes. One volume held the rules of using the scheme and the other held the schedules needed to use it. Ranganathan, a mathematician by education, first thought of the scheme while studying in London, soon after his appointment as the first official Librarian at the Madras University Library in 1924. He studied at the London School for Librarianship and was greatly influenced by W.C. Berwick Sayers, a professor there.

He was often frustrated by the limitations of library classification schemes that he studied, which included the Library of Congress scheme and Dewey Decimal Classification. He felt that the schemes contained flaws because they were developed in order to organize existing collections. He felt there was a need to create a scheme that would be able to reflect forthcoming titles with different subject matter than had been seen in the libraries and to expand to new areas of knowledge over time. His Colon Classification scheme was developed to fill this need. He claimed that he was partly inspired by the demonstration of a child’s toy set, called a Meccano set, at a Selfridge’s department store in London. The Meccano set was similar to an Erector Set, containing blocks, loops, string, and other items that could be used to build many different structures.

As Ranganathan traveled back to India after his studies, he worked on the scheme that would eventually become Colon Classification. He tested it on the ship’s library. He then tested it on the Madras University Library and determined that it was ready to be published. The name comes from the use of the colon as the character to differentiate the pieces of the Class Number, which is comparable to a Dewey number. Colon Classification includes an additional guide for creating what it calls a Book Number. The Class Number and Book Number work together to give individual volumes a place on the shelf. What I will focus on in this discussion is the Class Number, which outlines the subject or topic of the book.

The 2nd edition of the Colon Classification standard was published in 1939, after several years of use and testing by the public. Ranganathan referred to this as the Basic Version of the Colon Classification scheme. In 1952, Ranganathan published the 4th edition. This included a major new development, the introduction of the PMEST (Personality, Matter, Energy, Space, Time) categories. The basic idea of five categories was present in the earlier edition, but was not clearly defined. The presence of information in any of these five categories is indicated by different punctuation, making the term ‘colon classification’a slight misnomer. However the name remains.

Description of Colon Classification

Ranganathan based the Colon Classification scheme on the concept of facet analysis, an idea that was not new to library science. He believed that any concept could be built by using a term from a basic class to start the concept at a very broad level and then adding terms that corresponded to facets of that basic class in order to arrive at the very specific topic. This is how his fascination with the Meccano building set came to life in classification. A Class Number was made up of a Basic Class number (or sometimes more than one, as we’ll see later) and as many additional facets (what he called Isolates) that the cataloger needed to add. The Basic Class number is sometimes referred to as the Basic Subject or the Basic Facet.

Each of the five types of facets is associated with different punctuation. The punctuation indicates what type of facet would follow:

, (comma) = Personality

; (semi-colon) = Matter

: (colon) = Energy

. (period) = Space

‘ (apostrophe) = Time

Notes about this punctuation: Catalogers were allowed to omit the comma before the Personality element.

To be exact, the apostrophe did not appear until the sixth edition, published in 1960. Before then, a period was used for both Space and Time.

The letters and numbers used in each area were and are listed in official Colon Classification schedules. The number of Basic Classes is quite small. In 1933 the list consisted of 26 items, one for each letter of the alphabet. The number expanded to 46 in the 1960 edition.

The Personality, Energy, and Matter values vary according to subject. The Time and Space values are much more regular across all subject areas. Also, Ranganathan named in 1933 a small number of common subdivisions such as Bibliography, Maps and charts, Biography, History, Statistics, etc. which are used across all subject areas.


So, for example, consider a book or report about ‘Circulation of periodicals in University Libraries in India up to the 1970s’. Using Colon Classification, this book/report would have this Class Number:


This Class Number breaks down like this:

2 = Basic Class number 2, indicates the Basic Class Library Science.

34 = Personality. (Notice the lack of comma, as mentioned above.) In the Library Science Basic Class, Personality indicates types of libraries. 34 is the number for university libraries. In fact, 3 indicates any type of academic library, and 34 is a narrower term, so an additional digit is added to it. 33 indicates college libraries, 42 indicates industrial libraries, 48 indicates government department libraries, etc.

;46 = The semi-colon indicates a Matter value. In the realm of Library Science, Matter indicates the type of materials involved. 46 corresponds to periodicals.

:6 = The colon indicates an Energy value. In the realm of Library Science, Energy facets describe common actions such as cataloging (55), circulation (6), reference service (7), book selection (81). Please note that numbers in Colon Classification are in decimal order (not whole number order), so these four examples are listed in correct ascending order.

.44 = The period indicates a Space value. 44 is assigned to India. The scheme includes the number 1 to indicate World, as well as numbers to indicate specific states/provinces in some countries, such as 7376 for the state of Illinois.

‘N7 = The apostrophe indicates a Time value. The initial letter indicates a century (N=1900-1999), while the 7 indicates a decade. (Ranganathan was thinking far ahead: in his original schedules published in 1933, he had a table of values that went up to Z, which stands for the years 3000-3099 A.D.)

The five facets always are placed in this order. In some cases libraries have become accustomed to omitting some of the punctuation because it is “self-evident” that a new facet has begun. However I found this extremely confusing for someone who is new to the scheme.

About the five facets

Many catalogers and theorists have struggled with the distinction between Personality, Matter, Energy, Space, and Time.

Space and Time are the easiest of the five to understand. However, it is important to note that these are meant to be facets of some other concept—when they are the main focus of a work in themselves, then they are considered to be Personality elements of the work’s Class Number.

The Matter facet typically deals with some concrete object, typically inanimate. This includes basic elements/materials as well as finished products. This category also includes adjectives to describe inanimate objects.

Energy indicates action and interaction. This could be persons, objects, or any entity acting alone or with another. This could include conceptual or intellectual entities as well.

The Personality facet indicates the core point of the subject at hand. It is the most “elusive” of the five, as Ranganathan himself admitted in the 4th edition. In fact, he even admitted that if a concept could not easily fit into the other four categories then it is probably a Personality facet. I believe the Personality element requires the most intuition, as it is the cataloger’s gut feeling about what the most important element of the subject is. In many cases the Personality element is indicated by a Basic Class number only.

Ranganathan also allowed for the combination of two subjects from entirely different disciplines within a single Class Number. In this case, the cataloger added another Personality element onto the end of the initial (and most important) subject, along with the other relevant facets of the second subject. (This is the basic idea, although it is complicated by specific rules of order and number of facets allowed, etc.)

The future of Colon Classification

While Colon Classification, as well as many of Ranganathan’s ideas, continue to influence library and information science, the scheme is not widely used in libraries. It gained a foothold in India during Ranganathan’s life, but it never was the most commonly used scheme in India. Its critics claim that the scheme is better suited for classification of academic libraries than public or general-interest libraries. Colon Classification was also criticized because of major changes from one edition to the next. This not only added a burden of retrofitting to the libraries that used the scheme, but it also gave the international community the impression that Colon Classification was a work in progress rather than a fully functioning scheme. (Criticism about changes to the scheme particularly irritated Ranganathan. He pointed to his fifth law of library science, that a library is a growing organism. He extended this law to include classification of the library.) Most importantly, critics have long maintained that the Colon Classification notation and code numbers are simply too complex to gain acceptance from average library patrons.

Unfortunately, when Ranganathan died in 1972 he had not left an organization in place to continue work on the Colon Classification. All of the updates to the Colon Classification were personally managed by Ranganathan (with a little help from assistants on the development of schedules). So the code did not have the benefit of an overseeing organization to continue work on the code and develop support for its use. Ranganathan was working on the 7th edition of the Colon Classification system when he died. This was finally published in 1987.

Despite its bleak future as a modern, living standard for classification, Colon Classification continues to have great influence in the library world. And at least one article I read wondered: what would Ranganathan have done with classification of the Internet?