Library Catalog Subject Search
Subject Heading Searches
When you do a subject search in the library catalog, you're looking for books, journals and other materials using particular subject headings, which are just terms used to describe a topic and group all materials on that topic together. The Library of Congress (LOC) creates and assigns these subject headings.
It's like when you go to Wegmans and find all the Coke, ginger ale & other carbonated beverages stocked together in the aisle labeled "soft drinks," even though you might call them soda or pop. According to the grocery store's subject headings, they're all soft drinks and they're all grouped together in aisle seven of the store. 
Similarly, in the library catalog, all materials on milk cows are filed under the LOC subject heading "dairy cattle," while you'll find stuff on TV commercials using "television advertising."
When you do a keyword search, on the other hand, the catalog will look for your term in every field of every record. It will look in the title, the abstract, subject headings, notes--everything. You can use whatever words you want for your keyword search, but you may very well miss some records that don't contain those particular words or phrases. Like if you wander into a Kwik E Mart and ask for a Coke--you'll get a caffeinated cola drink in a red can, but not every cola in the store.
Performing a Subject Headings Search
1. Identify the right subject heading
• You can consult one of the red Library of Congress Subject Heading books in your library or ask for assistance at your library's reference desk.
• Or begin by doing a Guided Keyword Search on your topic--just plug in what you think best describes your topic. When you get results, open one that looks promising. Then use the "Long View" to show the assigned subject headings. See Extended Tip below for more on this strategy.
2. Once you have identified the right subject, type it in the Search for box 
3. Click Subject Heading in the Search by box
4. Click Search.
Search Tips
• A common cause of failed subject searches is using phrases in your subject searches that aren't bona fide Library of Congress Subject Headings. Again, if you do a keyword search, you can use any words or phrases you like. But for subject searches, you have to use the assigned terms. A subject search for pigs, for example, will get you almost nothing. Look for swine instead. 
• Punctuation--including commas, periods, apostrophes, and dashes--is not necessary; for example, you can enter sir for "Scott, George Gilbert, Sir." That's Sir George on the right--famous English architect.
• To narrow your subject heading search, include all hyphenated terms found in the subject heading. Dashes are not required. For example, searching "hotels employees labor unions united states" will get you fewer results than "hotels employees."
• Subject searches are automatically truncated--that is, they retrieve all records that begin with the words or phrases you enter. For example, if you type "neuron," you will retrieve records for neuroanatomy, neurobiology, eurology, neuromuscular diseases, etc.
• Looking at the long view of a record will show you all the subject headings assigned to a record. A subject search for Natural Resources--Thailand, for example, will offer results with other subject headings such as Biodiversity Conservation--Thailand and Forestry and Community and Rural Development--Thailand. These additional subject headings are good ways to find more info on your topic.
• Speaking of more info, look for the "More Info" buttons when searching on subject headings --they can lead to additional or related subject terms on your topic. 
For example, if you search on the term alternative agriculture, you will see the "More Info" button on the left in the headings display. When you click the button, it produces a table showing narrower terms (permaculture) and related terms (sustainable agriculture).
Extended Tip: Keyword Search First, Then Subject Search
1. Do a subject search on the phrase standardized testing. Notice that your search doesn't retrieve any headings on this topic. Why? Not because Cornell doesn't own any books on the topic. Rather, it's because standardized testing is not a Library of Congress subject heading (LCSH).
2. Switch to a guided keyword search and search on standardized testing as a phrase. This time you get a few hits. After reviewing records in the "Long View," you will discover that Achievement Tests--United States and Educational Tests and Measurements--United States are the subject headings you need to use.
3. Now, just click the on either or both of those headings to redirect your search to the correct subject headings. You can also remove "United States."
4. You can try this approach with any research topic--do a keyword search first, using what you think is the best term for what you're looking for. Then look at the subject headings in the long record of a citation.
