Features of the Dewey Decimal Classification

Decimal Classification is an almost enumerative scheme of classification. Since 1876 to 2011

rd
(23 edition) this scheme did not look back, and its popularity has grown day by day throughout

the world. This statement can be justified by the fact that DC has been translated into many

languages, such as Chinese, Spanish, Danish, Turkish, Japanese, Hindi, Portuguese, Sinhalese and

several other languages across the globe. Dewey introduced the notion of using notation for the

subjects in his scheme and applying the notation to the book and not to the shelves. But certain

features forming the basis of its present form can be still recognized as follows:

1. Universal Scheme – A distinctive feature of the DC is that its classes reflect all the areas of

specialized knowledge developed in modern society. These specialized areas are loosely put

together in the main classes in the scheme, albeit in this manner the principle of collation of

bringing of related subjects in close proximity is sometimes violated.

2. Relative Location – In his scheme, Melvil Dewey introduced the brainwave of ‘relative

location’ as opposed to ‘fixed location.’ For this purpose, he utilized the decimal notation

consisting of Arabic numerals for the subjects and assigning that notation to the books on the

basis of thought content and not on the basis of the shelves. In this method, a new book on a given

subject may be put in between the existing sequence at the required position, directed by the

notation assigned to that book and there is no necessity to put the book at the end of the sequence

as had been the practice in “fixed location.”

3. Decimal Notation – Melvil Dewey used decimal fraction notation for the arrangement of

knowledge on the shelves. Indo-Arabic numerals (0 to 9) are used decimally for the sub-divisions

of knowledge. In this process, the universe of subjects is divided into ten main classes, each of

which is again divided into ten divisions. Again each division is further divided into ten sections.
At each stage of division, a given number is sub-divided decimally. All the class numbers in DC

are decimal fractions.

4. Minute Division – The first edition of DC consisted of only 42 pages and at that time, it was

criticized for its being too broad in its sub-division. The number of pages had since been

increasing as shown in Table 1. This growth suggests the enormous number of sub-divisions

which are possible and useful for minute classification. Dewey emphasized the need of minute

division as “the advantage of close classing is unquestioned if the user knows just what it is.”

5. Mnemonics – Another important feature of DC is mnemonics, which means ‘aid to memory.’

In DC, mnemonics are available for subject synthesis. The use of consistent order in the subject

division of different classes produces mnemonics. There are various tables, such as, Area Table,

Language Table, Standard Division Table, etc. which are used to achieve subject synthesis. The

user may also find Scheduled Mnemonics, Systematic Mnemonics and Alphabetical Mnemonics

at a few places in DC.

6. Integrity of Numbers – One of the most important features of DC is the integrity of numbers.

To incorporate new developments and to keep pace with the growth of knowledge, a scheme of

classification should be revised continually, without changing the basic structure, so that the

professionals may accept the revised edition without hesitation.

7. Auxiliary Tables – Auxiliary tables provide an important basis for preparing numbers and lead

to uniform meanings of numbers when used in various contexts. A document, which is a source of

knowledge, always has some physical form. Melvil Dewey in the second edition of the scheme

published in 1885 introduced the concept of “Form Divisions” to be used for the sub-divisions of

a subject based on the characteristics of documents, either in accordance with the point of view of

the author, i.e. Bibliographical, Philosophical, Theoretical, Historical or in accordance with the

form of thought content in documents, i.e. Digest, Manual, Monograph, Dictionary, Periodical or
 Manual. The “form divisions,” could be attached to any class number according to the instructions
th th
provided therein. The system of ‘form divisions’ remained in use up to the 12 edition. The 13

edition consisted of 5 “Auxiliary Schedules.” The 14 th edition had 4 tables. In the 15th edition,

the conventional 9 form divisions, i.e. 01-09 were annexed along with the tables, without any

detailed sub-divisions. The word ‘Form divisions’ was replaced by “Standard Subdivisions’ in the

17th edition, along with new area table in volume 2 (Index). The 18th, 19th and 20th editions

consist of 7 auxiliary tables which are detailed under DDC 20.

Structure of Dewey Decimal Classification

1. Schedule - A basic premise of DDC is that it is arranged by discipline and not by subject. At the

broadest level, the DDC is divided into ten main classes, which together cover the entire world of

knowledge. Each main class is further divided into ten divisions, and each division into ten

sections (not all the numbers for the divisions and sections have been used). The three summaries

of the DDC are as given:

2. Summaries – Summaries provide an overview of the intellectual and notational structure of

classes. Three types of summaries appear in the schedules and tables of DDC. The summaries of

the schedules as a whole are found at the front of the schedules (Volume 2-3). Single level

summaries in the schedules and tables provide an overview of classes that have sub-divisions

extending over more than two pages. Multi-level summaries are provided for eight major

divisions and the Area Tables for Europe and North America.

The First Summary: Contains the ten main classes. The first digit in each three-digit number

represents the main class.

 First Summary of DDC

000 Computers, information & general reference

100 Religion

200 Philosophy & psychology

300 Social sciences

400 Language

500 Science

600 Technology

700 Arts & recreation

800 Literature

900 History & geography

The Second Summary: Contains the hundred divisions. The second digit in each three-digit

number indicates the division.

The Third Summary: contains thousand sections. The third digit in each three-digit number

indicates the section. Thus 530 is used for general works on physics, 531 for classical mechanics,

532 for fluid mechanics, 533 for gas mechanics. Arabic numerals are used to represent each class

in the DDC. A decimal point follows the third digit in a class number, after which division by ten

continues to the specific degree of classification needed.

3.8.3 Relative Index

Relative index is appended to the schedules of o book classification. It is the most important

feature of this scheme; arranged in an alphabetical order and aims to include all topics expressed

or implied in the main tables together with every likely synonym. The index is comprehensive one

but exhaustive. The topics which are further sub-divided in the table are entered in the bold face
type. The specific items in the sub-divisions are entered directly under their own name. The index

is relative in the sense that each phase of the subject is noted. If a topic is treated in two or more

classes, the number it takes in each group is taken. The use of the index is not limited to locating

topic in the tables, it has equal value in locating topic on the shelves and in fact the reader’s key to

the shelf arrangement in every library in which the DDC is being used.

Acknowledgments

• I would like to thank and acknowledge the authors of various information sources and

references used to prepare this material.

• The content is prepared to help the students to understand the topic properly.

• The course content is solely prepared for the academic purposes.