Understanding Call Numbers

Not Quite Nuclear Physics But Close...

Each book in the library has a unique call number. A call number is like an address; it tells us where an item is located in the library. The Michael Schwartz Library assigns call numbers to its books, teaching materials, videos, sound recordings and other items it owns.

The Michael Schwartz Library, like many academic libraries in the U.S., uses Library of Congress Classification for call numbers. This system uses a combination of letters and numbers to arrange materials by subject.

Below is an example of how a Library of Congress call number appears on the spine of the book, Nuclear and Particle Physics and on its record in SCHOLAR.

What Does It Mean?

The title of the book we are using in our example is Nuclear and Particle Physics by W.S.C. Williams and published in 1991.

• The QC at the top of the label represents a general subject area which in this case is Physics.
• The 776 on the next line narrows the subject down to Nuclear and Particle Physics.
• The .W55 on the third line is a code (commonly called a cutter number) that represents the author's last name, Williams.
• Finally, the 1991 in the last line is the publication date of the book.

Keep in mind that this is a very basic example. Some call numbers can get fairly complicated and have more elements or even fewer. It may or may not have a publication date or instead of a publication date, have a volume number.

Reading a Call Number

Read a call number line by line. Again we'll use our example, Nuclear and Particle Physics.

• The first line (QC) should be read in alphabetical order, placing this book after any books labeled QB but before any books labeled QD.
• The second line (776) should be read as a whole number, placing this book after any books labeled QC 775 but before any books labeled QC 777.
• The third line (.W55) is a combination of a letter with numbers:
  • Read the letter (W) alphabetically, placing this book after any books labeled QC 775 .V but before any books labeled QC 775 .X.
  • Read the number (55) as a decimal, placing this book after any books labeled QC 776 .W5 or say QC 776 .W54 but before any book labeled QC 776 .W56 or QC 776 .W6.
• The fourth line (1991), in this case, is the date of publication and should be read chronologically, placing this book after any books labeled QC 776 .W55 1990 but before any book labeled QC776 .W55 1992.

Finding It On the Shelf

So now you want to go get Nuclear and Particle Physics from the shelf. The record in SCHOLAR tells you that it is on the 4th floor. If you missed the location in the SCHOLAR record, you might have found the location from our Book Locations Web page or from floor plans.

When you get to the 4th floor, find the row of shelves that includes books with the first 2 lines of your call number, QC 776. Signs on the end of each row of shelves will tell you the range of call numbers you will find on the books shelved there, in this case the sign on the shelf we need reads QC 611 - QC 787 .

Browse the shelves until you narrow it down to QC 776 and then look for the next element of your call number, .W55. Note in the picture at the right how it comes after QC 776 .M3 and QC 776 .P74, following alphabetically the third element in the call number.

An advantage to classifying books by subject, is that you can often find several helpful books on the same shelf or nearby the book you were looking for. So in finding Nuclear and Particle Physics on the shelf, you also see right next to it Nuclear and Particle Physics, which might also be useful for your research.