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Print Resources and Search
Strategies:
Subject Headings & Classification Systems
Sections:
1) Types of Print Resources
2) Subject Headings & Classification Systems
3) Call Numbers
4) Author, Title, Subject & Keyword Searching
5) Quiz
THE
ORGANIZATION OF LIBRARY MATERIALS
Imagine that you're a bookworm, constantly buying and reading new books. At
first, your book collection is small enough that you simply add your new
purchases randomly to your bookshelf in no particular order. But by the time
it grows to 100 or more books, you decide to organize your collection so that
you can find what you need easily without a lot of wasted time and effort.
You could arrange your books by author, title, color, size, date purchased,
language, hardback vs. paperback, or many other ways. Any of these approaches
is perfectly valid for an individual with a relatively small collection, but
libraries use none of these approaches. How do libraries – which
contain thousands and in some cases millions of books – arrange their
collections?
Libraries
organize their collections according to subject
matter. This is an enormously complex, evolving project that is based on
three organizational tools: subject headings, classification systems, and
call numbers. Call numbers will be discussed in the next section.
SUBJECT
HEADINGS
When a book or other item is added to a library's collection, a specialist
known as a cataloger examines it and decides what the book is about. The
cataloger must describe the subject content of the book as completely as
possible by using standardized, officially approved words or groups of words
known as subject headings. He/she
will assign between 1 and 5 subject headings to describe the content of a
book. Subject headings assigned by a human cataloger make it possible for you
to do a subject search.
Subject
headings can be one word, two or more words, a phrase, a city, a country, a
geographic region, or a person. The following are all valid subject headings:
HOSPITALS
ELECTROCHEMISTRY
WOMEN IN MOTION PICTURES
DATABASE MANAGEMENT
FRANCE -- ECONOMIC CONDITIONS
DATABASE MANAGEMENT
HEMINGWAY, ERNEST
Sometimes,
the first word or phrase that comes to your mind is, in fact, the
"correct" (i.e., the valid) subject heading. For example, books on
CHILDREN'S LITERATURE or PHOTOGRAPHY may be found under those subject words.
At other
times, however, subject headings are expressed in less obvious terms. For
example, you may look up the subject MOVIES in a catalog or index and find
nothing. Then you try FILMS – again, no luck. You might assume that
there is no information on the subject, but there are in fact many books and
articles on movies under the subject heading MOTION PICTURES.
Listed
below are more examples of topics with subject headings that wouldn't
immediately come to mind:
Topic:
Finding a job
Subject Heading:
APPLICATIONS FOR POSITIONS
Topic:
The American Revolution
Subject Heading:
UNITED STATES -- HISTORY -- REVOLUTION
Topic:
Medieval art
Subject Heading:
ART -- MEDIEVAL
Topic:
Date rape
Subject Heading:
ACQUAINTANCE RAPE
Topic:
Sleeping sickness
Subject Heading:
AFRICAN TRYPANOSOMIASIS
Topic:
Southeast Asia
Subject Heading:
ASIA -- SOUTHEASTERN
As you can see, subject headings often use very formal language. Given below
are some other characteristic features of subject headings:
*
Subject headings are usually given in plural form. Thus, SHARKS is used
rather than SHARK, and APARTMENT HOUSES rather than APARTMENT HOUSE.
* In
general, slang, jargon, and highly specialized terminology are avoided in
subject headings in favor of standard English. For example, drunkenness will
not be found under terms such as "smashed," "bombed," or
"wasted." Valid headings for drunkenness include ALCOHOL ABUSE,
ALCOHOL DRINKING, and SUBSTANCE ABUSE.
*
Subject headings are sometimes inverted to emphasize the most important word.
In such cases, you can determine the correct subject heading by simply
reversing the words you're likely to think of first. For example, the subject
heading for information on abstract art is ART, ABSTRACT. For American
authors, the heading is AUTHORS, AMERICAN.
SUBDIVISIONS
- ADDING PRECISION TO A SUBJECT HEADING
Since
subject headings often cover somewhat broad concepts, additional words called
subdivisions (sometimes called subheadings) are often added as a way to focus
on a more specific aspect of the subject. Subdivisions are separated from the
main heading by a dash (--) and identify various aspects of a subject that
may be of interest to you. For example, AIRPLANES is a valid, but very broad,
subject heading. Many subdivisions, however, can be found which focus on
specific aspects of airplanes. Listed below are only a few of the many
subdivisions under the main heading AIRPLANES:
AIRPLANES
-- BRAKES
AIRPLANES -- DESIGN AND CONSTRUCTION
AIRPLANES -- FUEL CONSUMPTION
AIRPLANES -- INSPECTION
AIRPLANES -- SPEED
AIRPLANES – WINGS
Subdivisions can be one of four types:
* Topical subdivisions narrow the
subject to a particular aspect. The subdivisions in the above example on
AIRPLANES are all topical subdivisions. Other examples of main headings
followed by topical subdivisions include:
CORN --
HARVESTING
WOMEN -- EMPLOYMENT
MASS MEDIA -- SOCIAL ASPECTS
* Geographical subdivisions narrow
the subject to a particular geographic area, such as a country, state or
city. For example:
MASS MEDIA
-- UNITED STATES
* Form subdivisions specify a
particular type or form of publication. They tell you about a book's type rather
than its subject. For example:
MASS MEDIA
-- DICTIONARIES
MASS MEDIA -- HANDBOOKS, MANUALS, ETC.
* Chronological subdivisions
narrow the subject to a specific date or time period. They are commonly seen
when dealing with historical subjects. For example, when searching for
information on any aspect of American history, always start with UNITED
STATES -- HISTORY and then add a chronological subdivision such as:
UNITED STATES -- HISTORY -- 19TH CENTURY
UNITED STATES -- HISTORY -- 1865-1877
LIBRARY
OF CONGRESS SUBJECT HEADINGS (LCSH) : A CONTROLLED VOCABULARY
Now
that you know a little bit about subject headings, you may wonder where they
come from. Who decides on the exact word(s) and subdivisions that become an
officially approved subject heading? These decisions are made by specialists,
known as catalogers, who work for the largest library in the world: the
Library of Congress in Washington, D.C. Almost every library in the United
States uses the subject headings decided upon by catalogers at the Library of
Congress.
In order
to be consistent in their work, catalogers assign subject headings chosen from
a standardized, official list. This list of approved subject terms is known
as a controlled vocabulary. The controlled vocabulary used by catalogers at
the Library of Congress is known as the Library of Congress Subject Headings,
or simply LSCH.
Why should
a controlled vocabulary system matter to you, the researcher? Simply stated,
if you pay attention to subject headings, you can take advantage of the order
and precision it attempts to bring to the database. Although the formal
language used in subject headings can sometimes lead to problems when doing
subject searching -- i.e., you may not be able to "guess" the
correct term(s) -- you should at least be aware of the existence and purpose
of controlled vocabularies.
CLASSIFICATION
SYSTEMS
As you know, libraries organize their collections according to subject
matter. This arrangement is intended to be convenient for library users,
since books on the same subject are placed together on the same shelf. But in
order for subject-based organization to accomplish its goals, it must be
based on a definite and established plan that can be referred to again and
again. Therefore, libraries have created classification systems. A
classification system is an established plan that divides all knowledge into
precise categories and subcategories. Each category is called a
"class" and each subcategory is called a "division" or
"subdivision." This division of knowledge always proceeds from
general classes to more and more specific subdivisions.
Although
most public libraries use the Dewey Decimal system, most college and
university libraries (including CSM) use a different classification system:
the Library of Congress classification system. Devised in 1897, the Library
of Congress system (or LC system) is a comprehensive, highly detailed,
subject-based organization system that uses combinations of letters and
numbers to represent subject areas.
LC
divides all knowledge into 21 main classes indicated by a single letter of
the alphabet :
A
General Works
B Philosophy, Psychology, Religion
C History: Auxiliary science
D History: General and Old World
E-F History: America
G Geography
H Social Sciences
J Political Sciences
K Law
L Education
M Music
N Fine Arts
P Language and Literature
Q Science
R Medicine
S Agriculture
T Technology
U Military Science
V Naval Science
Z Bibliography and Library Science
There is
one final point to make about classification systems. Theoretically, a
classification system should work in such a way that books on any one subject
would be found in only one place. However, this becomes impossible for those
books that deal with more than one
subject. For example, a book such as Women,
Philosophy, and Sport: A Collection of Critical Essays could be
classified under women's studies (HQ), philosophy (B), or sports (GV), which
are far apart from each other on the shelves. However, only one class number
can be assigned to this book. The cataloger will have to examine the book and
choose the class number that corresponds to the subject covered most
prominently by that book. Subjects covered in the book but not reflected in
the call number chosen by the cataloger will be described by additional
subject headings assigned by the cataloger.
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