A call number is the address of a book on the shelf.  Use the library online catalog to find the call number (location) of any item in the library.  The call number is listed at the bottom of the catalog record; it is also found on a label attached to the spine of the book (or elsewhere on the item).  In our library, we use three kinds of call numbers:

1.  Library of Congress Call Numbers:

Library of Congress call numbers use the Library of Congress Classification system to arrange books and other items by subject.  This means that when you find the book you are looking for, other books on the same subject will be close by.

In our library, Library of Congress call numbers are used for materials in the following collections:

• General Collection:  Circulating books and bound periodicals, shelved on the Top Level
• Reference:  Non-circulating reference books, shelved on the Middle Level, north end
• Current Periodicals:  Non-circulating current issues of magazines and journals, shelved on the Middle Level, south end
• Media:  Videos, compact discs, etc., shelved on the Lower Level.

For example, the call number (location) for the reference book set called CQ Researcher is:

• Reference tells you that the book is located in the Reference Collection, Middle Level
• H35 identifies this as a general social sciences book, and it will be near other general social science titles. This is based on the Library of Congress Classification.
• .E2322 is added to provide a unique number for this title.
• To find this book:
• go to the Reference collection
• find the section where the call numbers on the book spines start with H
• find H35 (it will be after H10, H20, H30 and H34)
• then find the book with .E2322 after the H35

2.  Dewey Decimal Call Numbers:

Dewey Decimal call numbers use the Dewey Decimal Classification system to arrange books and other items by subject.  This means that when you find the book you are looking for, other books on the same subject will be close by.

In our library,  Dewey Decimal call numbers are used for materials in the following collections:

• Young People:  Circulating books for young people, shelved on the Lower Level, north end.
• Curriculum:  Circulating curriculum related materials, shelved on the Lower Level, north end.
• Special Collections:  Non-circulating books and other materials, located on the Top Level, south end
• Archives:  Non-circulating archival materials, located on the Lower Level, south end (enter through the west outside door on the Lower Level)

For example, the call number (location) for Harry Potter and the Sorcerer's Stone is:

• YP tells you that the book is located in the Young People collection, Lower Level, north end
• 813 identifies that this book belongs to the category of fiction in English.  This number is based on the Dewey Decimal Classification system.
• .R88 is a number based on the last name of the author, J. K. Rowling
• 4h is added to create a unique number for this title.
• 1998 is the year the book was published,  
• To find this book:
• go to the Young Peoples collection
• find the section where the call numbers on the book spine starts with 813
• find .R88 (after .R10, .R70, .R80)
• then find the book with 4h and 1998 after the .R88

3.  Superintendent of Documents Call Numbers:

Materials in the Government Documents collection (Middle Level, north end) are arranged by government agency using the Superintendent of Documents Classification system.   See our Overview of this system for an explanation of how to these call numbers work.