A keyword is a word or phrase that describes the main concepts of a topic. Before you start searching it is a good idea to brainstorm synonyms and combinations of terms. This will increase your chances of finding information on a topic.
For example, if your topic was capital punishment, other keywords might include death penalty, death sentence, execution, etc..
Boolean searching is a method that allows you to combine multiple concepts within a topic. This is done by using the following connectors: and, or, not. And is most frequently used to narrow a topic, e.g., 'death penalty' AND race would retrieve all items pertaining to both topics and no items pertaining to either topic by itself. Or is used to expand a topic, e.g., 'death penalty' OR race would retrieve all items pertaining to either topic, which means you would retrieve many items about race that don't mention the death penalty and vice versa. Not is used to exclude unwanted topics, e.g., 'death penalty' NOT race would retrieve items only pertaining to the death penalty and would retrieve no items pertaining to both.
Below are some examples of Boolean searches.
Boolean operators are not necessary in our main book and article search tools.
Quotation marks should be used around a phrase or concept of two or more words. Doing this ensures that the concept will be searched for as a whole and not picked apart by the search engine. For example, typing death penalty without quotation marks could potentially retrieve all items that mention death, all items that mention penalty, as well as all items about death penalty. This could lead to results that seem to have nothing to do with your topic, e.g. funeral rites in India or penalties in hockey. For best results, use quotes. For example: "death penalty", "death penalty" and race, or "death penalty" and "race relations".
Subject headings are a set of controlled vocabulary used to classify materials. Most library catalogs and databases include subject headings (sometimes called descriptors). You can use subject headings to improve the accuracy and efficiency of your searching.
A controlled vocabulary is a restricted set of words used to describe things. The yellow pages, for example, uses a controlled vocabulary to help you find listings (i.e., doctors, physicians, and medical practitioners are all listed under the same heading, allowing you to more easily find all of them together).
Likewise, book records in the library catalog have subject headings that describe the key topics of the books. Real subject headings include:
Finding subject headings that match your topic is a good way of locating library materials.