When researching in a library, especially a research library, its catalog is probably the most important tool you will use, and one with which you should familiarize yourself as quickly as possible. Even if you think you have never used the Library Catalog here, you probably have and just do not realize it, since "Easy Search", the Library's federated search engine, sends all queries to the Library Catalog along with several other online research tools.

A library catalog is a database of records that identify and describe resources owned by the library. Most of these records describe published resources like books. Use the catalog to find both print sources and digitized sources in the Library's collections.

Many research libraries today will dress their catalogs up with fancy interfaces, making the catalogs appear to have far greater functionality than they actually do. You will be a much better user of library catalogs if you understand the purpose and functions of library catalogs, which are in fact very basic:

1. The catalog should be an efficient instrument for ascertaining:
   • Whether the library owns a particular work specified by its title;
   • Whether the library owns a particular work specified by its author;
   • Which works by a particular author are in the library;
   • Which editions of a particular work are in the library.¹
2. The catalog should collocate records for works on a common subject under a single, standardized heading.

Digitization of library catalogs has made it possible to perform keyword searches on the records in the catalog. Aside from this innovation, and a few other conveniences, the library catalogs of today are essentially identical (in function) to library catalogs created a hundred years ago.

If the Library does not have the book you need, or else the book you need is charged, then you should next search the:

After you have explored the books available to you here at the University of Illinois, and also at other I-Share libraries, you will want to expand your search using:

If you find a book in WorldCat that you would like to use for your research, you can request it through:

It’s true that you can find sources on a topic by doing keyword searches. But if you limit yourself to keyword searching, you are likely to miss important material on your topic that uses other terms. If you only need two or three books, you can probably find what you need by doing keyword searches, but if you are doing historical research, you can’t afford to miss critical material on your topic. For a comprehensive subject search, search with subject headings as well as keywords.

A good way to identify subject headings for a topic is to do a keyword search in the online catalog using terms you think describe the topic and try to identify a few relevant books. Look at the full record for those books to see what subject headings were used, then do another search on those headings.

As a rule of thumb, use fairly broad headings, as well as the specific ones that describe your topic, in order to make sure you haven't inadvertently eliminated relevant material that is contained within works of larger scope. Most likely you will find multiple headings to describe your topic, and you should use all of them. You can narrow your search in the online catalog by combining subject headings (as a phrase) with keywords, using the “Advanced Search” option.

Subject headings can only be browsed in the:

• African American neighborhoods
• African Americans -- Civil rights -- Illinois -- Chicago -- History
• African Americans -- Housing -- Illinois -- Chicago  -- History
• African Americans -- Illinois -- Chicago
• African Americans -- Illinois -- Social conditions
• African Americans -- Migrations -- History -- 20th century
• African American women -- Illinois -- Political activity
• Bronzeville (Chicago, Ill.) -- Economic conditions
• Charities -- Illinois -- Chicago
• Chicago (Ill.) -- Bibliography
• Chicago (Ill.) -- Economic conditions
• Chicago (Ill.) -- Emigration and immigration
• Chicago (Ill.) -- Ethnic relations
• Chicago (Ill.) -- History
• Chicago (Ill.) -- Politics and government
• Chicago (Ill.) -- Race relations
• Chicago (Ill.) -- Social conditions
• Chicago (Ill.) -- Social life and customs
• Chicago (Ill.) -- Statistics
• Civil rights movements -- Illinois -- Chicago -- History -- 20th century
• Community organization -- Illinois -- Chicago
• Discrimination in housing -- Illinois -- Chicago
• Environmental policy -- Illinois -- Chicago
• Ethnic neighborhoods -- United States
• Hispanic American neighborhoods
• Hispanic American neighborhoods -- Illinois -- Chicago -- History -- 20th century
• Hispanic Americans -- Illinois -- Chicago
• Hispanic Americans -- New York (State) -- New York
• Housing -- Illinois -- Chicago
• Housing policy -- Illinois -- Chicago
• Illinois -- Race relations
• Italian Americans -- Illinois -- Chicago
• Labor and laboring classes -- Illinois -- Chicago
• Labor and laboring classes -- Illinois -- Chicago -- History
• Labor and laboring classes -- Illinois -- Chicago -- Political activities
• Meat industry and trade -- Illinois -- Chicago
• Mexican American neighborhoods
• Mexican Americans -- California -- Los Angeles
• Mexican Americans -- Illinois -- Chicago -- History -- 20th century
• Mexicans -- Illinois --Chicago -- History -- 20th century
• Migration, internal -- Illinois -- Chicago -- History
• Minorities -- Illinois -- Chicago
• Minorities -- United States -- History
• Near West Side (Chicago, Ill.) -- History -- 20th century
• Neighborhood -- Illinois -- Chicago
• Packing-house workers -- Illinois -- Chicago -- History
• Pilsen (Chicago, Ill.) -- History -- 20th century
• Public housing -- Illinois -- Chicago
• Puerto Ricans -- Illinois -- Chicago -- History -- 20th century
• Social settlements -- History
• Urban renewal -- Illinois -- Chicago
• Urban policy -- Illinois -- Chicago
• Urbanization -- Illinois
• Urbanization -- Illinois -- Chicago -- Bibliography
• Urbanization -- Illinois -- Chicago -- History
• Urbanization -- Illinois -- Chicago Metropolitan Area

As described in a previous page, you can also use subject headings to find primary sources in the Library Catalog. Use the Library Catalog's advanced search option and include one or more of these Library of Congress Subject Heading form subdivisions in your search:

• Correspondence
• Sources
• Diaries
• Personal narratives
• Interviews
• Speeches
• Documents
• Archives
• Early works to 1800

In order to browse a menu of subject headings in the Library Catalog, you must use an older Catalog interface:

After a new book is assigned subject headings, it is then “classified” according to either the Dewey Decimal Classification system (DDC), or the Library of Congress Classification system (LCC). Most of our new books are now classified according to LCC, but the bulk of the collection remains classified in Dewey. University of Illinois is the largest “Dewey” library in the world. In addition, we use a system called Superintendent of Documents Classification ("SuDocs") for U.S. government publications (based on issuing agency).

In Dewey, the first three numbers indicate the main subject, and additional numbers are added after a decimal point to narrow the subject. Books and journals on historical topics are usually classified in the 900s, although much of social history gets classified in the 300s, and the history of science, technology, and medicine is classified in the 500s and 600s. Religion is classified in the 200s, philosophy in the 100s, literature and literary studies in the 800s, and the fine arts in the 700s.

For more detail on the Dewey Decimal Classification, consult the Library's Guide to the Dewey Decimal System:

For more detail on Library of Congress Classification, consult the Library of Congress Classification Outline:

In order to browse the shelves, you need to know this “classification number”. Once you have identified a few books on your topic by doing a subject search in the online catalog, you can browse the shelf under the same general number(s) to find related works. For example, if you know that the book Popular Culture in the Age of White Flight: Fear and Fantasy in Suburban Los Angeles has the call number 979.494 Av55p, then you could go to the Main Stacks and browse the shelves under the same Dewey number to find related material. You can find dozens of periodicals for city administrators under the classification number 352.05. When you are browsing for periodicals, be sure to check for oversized periodicals as well, which are indicated with a "Q" (for "Quarto") before the classification number: Q. 352.05

Because so much of the Library collection is now stored in a high density, off-site storage facility, it's no longer possible to browse the collection as completely as it once was. You can, however, do "virtual shelf browsing" using the Library Catalog's Browse Search:

Ebooks include both books that were scanned from print originals (like those books in HathiTrust), and those that are actually released, for purchase, in a digital format (for example, those books you will find in collections like Project Muse Books). Books in the latter category might be released simultaneously in both ebook and print book formats, but an increasing number of scholarly monographs are being released only as ebooks (often freely available, or "open access").

Listed below are ebook collections, which have the obvious advantage of supporting full-text keyword searching across an entire corpus. Individual ebook titles are also discoverable through the Library Catalog (see above).

1. International Federation of Library Associations, Statement of Principles: Adopted at the International Conference on Cataloguing Principles, Paris, October 1961, ed. Eva Verona, Definitive ed. (London: International Federation of Library Associations Committee on Cataloguing, 1971), xiii.