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Research Tutorial

This tutorial aims to help develop effective library research skills and critical thinking skills in all courses at Prince George's Community College.

Library of Congress Classification System

Prince George's Community College uses the Library of Congress Classification System, an alphanumeric system, for classifying and locating books, videos, CD's, DVD's, and other sources. This system assigns each type of item a unique call number, which is its "address" and subject matter.

Call Numbers

Each call number contains both letters and numbers like an address to locate sources in the library. Books and other items can be found through accessing the online catalog.

 HV 6432 .C36 2001

Reading Call Numbers

Remember the Library of Congress Classification system arranges books and other items by subject. Fiction books are classified by a call number according to its subject. After the book is cataloged and processed, the call number is put on the spine of the book.

Books are shelved from left to right by the call number on the spines. They are arranged alphabetically according to the letter(s) of the first letter of the call number such as A, B, C, D, DA, DB, etc.

A

D

DT

F

Books that start with the same letters are shelved numerically by the number on the second line.  

HV
6431

HV
6432

HV
6435

HV
6437

Books with the same letters and numbers are arranged alphabetically by the letter and numerically by the third row. The number is read as a decimal.

HV
6432
.S592
1998

HV
6432
.S69
1996

HV
6432
.S743
2001

HV
6432
.S82
2002

Books sometimes require a fourth line when the first three lines are identical. The fourth line is arranged alphabetically by letter and then numerically.

HV
6431
.I6
C46

HV
6431
.I6
C47

HV
6431
.I6
C51

HV
6431
.I6
C58 

The last line of the call number may include dates, volumes, issues, and copy number. Editions of books with the same call number but have different dates are shelved in chronological order with the earliest date first.

What does a call number mean?

Remember that Library of Congress Classification arranges materials by subject. The first sections of the call number represent the subject of the book. The letter-and-decimal section of the call number often represents the author's last name. As you probably recall, the last section of a call number is often the date of publication.

For example:

Title What You Need to Know about Developing Study Skills, Taking Notes and Tests, Using Dictionaries and Libraries
Author Coman, Martha J.
Call Number LB 2395 .C65 1991
LB
2395
The first two lines of the call number describe the subject of the book.
LB 2395=Methods of study in higher education
.C65 The third line often represents the authors last name. .C65=Coman
1991 The fourth line represents the year of publication.

Source: Call Number, a section of LINKS: Module 1 by Lansing Community College.

LC Call Number Activity

Place these LC call numbers in correct order. Use the arrows to move the blocks up or down. Click on the check-mark icon to submit your answers. (To re-set the activity, click on the refresh icon).