|Basic Library Research Skills||
Southern Utah University
Google has made us comfortable with natural language searching. When searching Google you can type an English sentence describing the information you are looking for and you'll probably get some results. When databases like Google or Ask.com offer natural language searching programmed logic is used to determine the keywords in the sentence by their position in the sentence. This can work in very large online databases like Google with billions of pages to search, but the technique would give you very few results when searching a library article database which typically only has hundreds of thousands or a few million articles.
Online library databases require that you search for articles using search statements that are entered into the search box. These search statements include only the important words that describe your topic (e.g., keywords, phrases, or subjects) and these words can be entered into the search box with Boolean operators, truncation, limiters, and nesting to make your search more specific.
Research question: How do oil spills damage the environment?
Search statement: oil spill* AND damage AND environment
Research question: What dangers do school sports pose for students?
Search statement: danger* AND school AND sport*
Search statement: danger* AND school sport*
Research question: What foods do grizzly bears eat in the Yellowstone area?
Search statement: food* AND yellowstone AND (bears not grizzlies)
Computers index "significant" words in databases in the title, summary, subject or even the text fields of a record or article. These words are then searchable. When you type these words into the database search window, this is called keyword searching.
Keyword searches are best used when you're searching for new terms, distinctive words, jargon or slang. When keyword searching, databases do not index certain commonly used words and parts of speech, called stop words, such as articles, pronouns and prepositions. Examples of stop words in databases are a, an, about, after, all, also, and, any, are, as, at, based, because, been, between, and so on.
The disadvantage of keyword searching is that you only find records that contain the terms you type. You can miss synonyms of the terms you use. A keyword search may also find many more records than you want.
Boolean operators, named after British mathematician George Boole (1815-1864), can be placed between your search terms to narrow or expand a search, or to exclude search terms.
The Boolean operators are: AND OR NOT
In these examples of how to use Boolean operators, Venn diagrams are helpful to visually illustrate how these operators can be used:
Example 1: Your topic is "how exercise and health are related."
- This search will retrieve records with BOTH search terms present.
- AND is used to NARROW your search.
- The more terms you combine with AND logic, the fewer records you will retrieve. For example,
exercise AND health AND age
will retrieve even fewer records than Example 1.
Example 2: You are looking for "information on salary."
- This search will retrieve records with EITHER search term present. Your search includes both terms salary and income since records with either term could be useful.
- OR is used to EXPAND your search.
- The more terms you combine with OR logic, the more records you will find.
Example 3: Your topic is about bears, but not grizzly bears.
- This search will retrieve records with ONLY ONE search term present. The term bears will be found, but the term grizzly will not.
- NOT is used to NARROW your search by eliminating terms
By adding a symbol, sometimes called a wildcard symbol, to the end of a word, truncation allows you to search the "root" of a word to find all its different endings. The most common truncation symbol is the asterisk . However, some databases use different symbols, so check online help to find the correct symbol.
Example: You are looking for information "the banking industry."
bank* finds: bank banks banking bankers bankruptcy