Library Catalog Basics

Library Basics: Using the Catalog and Other Resources

Libraries are treasure troves of information, ready and waiting to answer your every question. However, navigating through their information and finding your answers can be intimidating for those new to a library.

We want to everyone to walk confidently into their local or school library, so we’ve put together this short guide to help anyone use a library catalog, locate materials on a shelf, understand what databases are, and determine if search engines are appropriate for your research.

Library Catalog
Libraries organize lots of items – sometimes thousands or millions of them! – in a special way, so that anyone can find an item they are looking for. No one expects you to memorize where every book is kept on the shelf. Instead, to help you find sources, librarians create catalogs which store information about every item in the library, and where you can find them.

The library catalog is like a search engine that helps you find items in your library. You can search for items by title, author or subject. You can also do a general search for keywords like “dinosaurs,” “Italian cooking,” or “voting rights”.

The main page of your library usually has a link to their catalog. If you are unsure of where to find this, ask a librarian. The library catalog may also be called an OPAC, which stands for an Open Public Access Catalog.

Each item in a library catalog has its own catalog record. Catalog records include information about an item such as the author, title, publishing date, type of item (book, DVD, map, etc.), the item’s status (available, checked out, lost, etc.) and the call number. The call number tells you where you can find an item in the library. Typically, nonfiction books have a combination of letters and number, while fiction books usually just have letters. Here are a few examples of call numbers:


“Catcher in the Rye” by JD Salinger – Call number: YA FIC Salinger

“The Night Circus” by Erin Morgenstern – Call number: FIC C


“Gulp” by Mary Roach – Call number: 612.3 R

“On the Origin of Species” by Charles Darwin – Call number: 576.82 D

The Dewey Decimal System
With so many items in a library, it is really important that they stay organized. Librarians use a classification system to organize items in a library. That way, people can easily find what they are looking for every time they come to the library!

Most schools and public libraries organize nonfiction books and other items using the Dewey Decimal System. University and college libraries tend to use the Library of Congress Classification System. There are other types of organization systems that libraries use, but we will focus on the Dewey Decimal System.

The Dewey Decimal System was invented by and named after a librarian named Melvil Dewey. His system is made up of numbers that are associated with general categories, like technology, art and religion.

For example, here is the outline of the first 5 categories:
  • 000’s – General Works
  • 100’s – Philosophy
  • 200’s – Religion
  • 300’s – Social Sciences
  • 400’s – Languages
The digits that follow the general category number are connected to more specific (and similar) categories, as we will see below. Together, these groups of numbers are called call numbers.

Call numbers tell you where to find nonfiction items in the library. You can find the call number in the catalog record, listed under Call Number, Location, Shelf Number, or something similar. Ask your librarian if you are unsure of where to locate the call number in the catalog record.

Breaking a Call Number Apart
The longer the call number is, the more specific the topic is. For example, let’s look at the 300’s category.

300 – Social Sciences
  • 310 Statistics
  • 320 Political Science
  • 330 Economics
  • 340 Law
  • 350 Public administration & military science
  • 360 Social problems & social services
  • 370 Education
  • 380 Commerce, Communications & transport
  • 390 Customs, etiquette & folklore
As the call number becomes more specific, so does the subject. For example, a general book about sociology would be in the 300’s. A book specifically about politics would be in the 320’s.

Let’s now examine a call number we found on women’s voting rights and break it down:

324.623 V

In the Dewey Decimal System, books organized within the 300 category are about the social sciences, such as politics or law. Items organized under the number 324 are specifically about the political process, such as acquiring voting rights.

Going into even more detail, books organized under 324.623 are about the women’s suffrage movements. The letter at the end (“V”) is the first letter of the author’s last name.

As you can see, there is a very organized process to keep books sorted. In fact, if you didn’t yet have a book selected, you could browse the 324 section of the library for voting rights books since you know that section is about the political process.

Call numbers are just like street addresses. They will tell you how to find what you are looking for!

Find It on the Shelf
In order to find your book on the shelf, you will need to see where books cataloged under 324.623 are stored. Most libraries have signs on the side of each bookcase with a range of call numbers, such as 125.3 – 178.8. If the call number of the item fits within this range, you will find it on that bookshelf!

Call numbers are printed on stickers that are placed at the bottom of the spine of a book. Items organized by the Dewey Decimal System on a shelf are sorted from left to right. In other words, you will see that the call numbers will increase as you move left to right, from the top to the bottom of the bookcase. Here’s an example bookshelf:

Nonfiction & Fiction
NONFICTION means that the content in the book or item is based on real events, people or places. These items are organized by their Dewey Decimal number.

FICTION books or items are organized by the author’s last name, and then by the title of the book. Many libraries organize fictional items in a separate section of the library.

Locating E-books in a Library Catalog
When you search an OPAC, you may also find e-books, or digital books, in the search results. These aren’t found on the shelves in the library, but online!
Sometimes, e-books are kept in a separate catalog from the books on the shelves. Check with your librarian to see if you can access e-books, and where you can find them.

There are other ways to find information through the library besides library catalogs. You might also be able to use databases. Databases provide access to credible content that is not always discoverable using a search engine on the Internet. In other words, databases allow you to search for and find reliable sources of information, like newspaper or journal articles, that are written by professional writers or experts.

Databases have lots of information on many different subjects, which makes them useful for all sorts of school projects. Unlike searching for information on the Internet with a general search engine, databases let you search a smaller amount of really reliable information!

Database companies charge a fee to libraries so that their users can access information within the databases. Libraries take money out of their budgets to pay for electronic databases so that you can have access to quality information!

Search Engines
Search engines are really useful tools for certain things. For example, if you want to find out what time a movie is showing at the mall, a search engine can help. In this situation, databases are not useful for finding that kind of information.

For most school projects, though, search engines are not the best option.

The quality of information found in search engines can be very different compared to information found in the library catalog or electronic databases. Search engines find information online by using things called web crawlers. Web crawlers are computer programs that collect information from all over the Internet and add it to the search engine so that you can find them easily.

However, the information that web crawlers find are not always written by experts, professional writers, and may even be totally made up!

Search engines are fast and return results quickly, but you may spend a lot of time looking through pages and pages of links on search engines. Even worse – you may come across unreliable information!

Why Should You Use Databases

There are many reasons why you should use databases for research. Here are three big ones:
  • Items found in databases are written by experts or professional writers
  • Databases search fewer items than search engines, making your research more manageable
  • It has a librarian’s approval as a useful resource!
Searching a smaller number of better sources makes finding valuable information easier!

Now that you know the basics, run to your school or closest public library and begin discovering information that interests you. Finding and borrowing books, videos, and other items is easy once you start; it’s stopping that tends to be hard.   —-
No matter what resources you find at the library, if you use it for your project, don’t forget to cite it! Cite easily in MLA format, APA format, Chicago, or more with BibMe citation tools.