Most libraries use one of two classification systems:  Dewey Decimal or Library of Congress.  Many of you are already familiar with the Dewey Decimal System because that is what our library and most public libraries use.  The Library of Congress System, however, is quite different.  It is the system used by most colleges and universities.  In order for you to find books easily and understand how books are shelved, you need to understand the call numbers for both types of classification systems.

Call numbers refer to the use of numbers and letters to designate the subject area and author of a text.  Every book has a number and the numbers designate where the book belongs in the library.

Using the Dewey Decimal system, books will have a number.  This number will usually be followed by a letter.  The letter corresponds with the author's last name.  For example, if the author's names was Smith, the letter would be S.

Books in the Dewey Decimal System are arranged in this way:
000-099  General Works
010-019  Bibliography
020-029  Library Science
100-199  Philosophy
150-150  Psychology
200-299  Religion
300-399  Social Sciences
320-329  Political Science
340-349  Law
355-359  Military Science (some of there are also in the 623 area)
359&623 Naval Science
370-379  Education
400-499  Language and Literature
500-599  Science
571-573  Anthropology
600-699  Technology
610-619  Medicine
630-639  Agriculture
700-799  Recreation and Fine Arts
780-789  Music
910-929  History:  Auxiliary Sciences
910-919  Geography
930-999  History:  General and Old World
970-979  History:  American

Understanding these call numbers, means that if you were looking for a book on Education, you could go straight to the 370s and skim the shelves for books of interest.

The Library of Congress System is quite different because it uses letter to classify by subject and then numbers identify more specific topics.  Like the Dewey Decimal system, Library of Congress also adds an additional letter to identify author's last name.  For example, the call numbers might look like this --
QH84A--meaning it is in section QH, under topic 84, with an author's last name beginning with an A.  Following are the subject groups for the Library of Congress System:
A        General Works
B        Philosophy, Psychology, and Religion
C        History:  Auxiliary Sciences
D        History: General and Old World
E-F     History:  American
G        Geography, Anthropology, and Recreation
H        Social Sciences
J         Political Science
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