 In this tutorial, you will learn the history, purpose, and deciphering of the Library of Congress classification to be able to efficiently find books for your research. The classification was developed by Herbert Putnam and designed specifically for the National Library of Congress to replace the original classification system developed by Thomas Jefferson. Unlike the Dewey Decimal System, it is a way to organize materials. However, the Dewey Decimal System is commonly used in public libraries, whereas the Library of Congress classification system is used in most academic libraries. A Library of Congress call number is comprised of letters and numbers. Each letter has a subject associated with it. For example, the letter Q encompasses the sciences. A second letter is added to define a more specific area of study within that subject. For example, QK designates botany within the sciences. Numbers are used to refine the subject even further. For example, in the call number range QK900 through QK989, you will find books on plant ecology. With this system of classification, it allows books on similar topics to be shelved together. So when you retrieve a book on the shelf, you can scan the other books beside, above, and below your book to find more good books on your topic. Call numbers are not randomly assigned, but created using the Library of Congress's prescribed subject areas. Taking a brief glance at all of the subject areas included in Library of Congress, you can see that this system brings order to the plethora of resources available. Call numbers are read line by line. We know that the first group of letters and numbers pertain to the book's subject. Usually, there is a decimal point with another alphanumeric sequence which designates the cutter number. This cutter number is used to differentiate the work from others on the same subject and to allow for easy retrieval of the book. The cutter number is treated as a decimal. For example, point A557 is shelved before point A75. When browsing the stacks, bookshelves are read left to right, top to bottom, and at the bottom of a section, you would go to the top of the next section. Major concepts in a book designate the call number assigned to that book. Topics are multifaceted, and books on a topic may be shelved in multiple call number ranges. For example, when doing research in social media, you may find books in H's, P's, and R's for social sciences, language and literature, and medicine. Can you find a book that answers this riddle? What goes on four legs in the morning, on two legs at noon, and on three legs in the evening? Brought to you by the Binghamton University Libraries and Open SUNY.