Locating Sources on Library Shelves

The call number that tells where a particular item is shelved may seem a random jumble of letters and numbers, but they are carefully chosen so that books on the same subject will end up next to each other on the shelves. College libraries generally use the classification system devised by the Library of Congress. If your library does, you'll find that call letters and numbers direct you to books and other items grouped in subject areas. Others use the older and more familiar Dewey Decimal Classification System, which files items into large categories by number. Some large libraries have both, having changed from Dewey to the Library of Congress system some time in the past. In any case, it can be fruitful to reserve some of your research time for browsing, because you will almost certainly find some materials on the shelf that are of interest next to the ones you found through the catalog.

You may notice that certain subjects aren't clearly included in either system—some fields, such as computer science, mass communications, and environmental studies, are newer than the classification systems themselves and so have had to be fit into other related areas.