Locating Information Using Search Terms
Now that you have decided on a topic, identified the kind of information you need, and developed a search strategy regarding the types of sources you will use, the next step is to select search terms or "keywords" from your topic to use to conduct your search. These keywords, which describe the topic you are researching, are the terms you will use when you search in any kind of electronic database, as well as on the Web.
Search operators, such as AND, OR and NOT, are terms that allow you to group your keywords together to retrieve a number of different types of results. Operators are words that may add or subtract a concept to your search. This is called Boolean Searching.
Boolean searching allows you to group words together in different combinations to produce a variety of results.
- Boolean - AND queries.
This is the most widely used Boolean operator. The query "second hand smoke" AND cancer will retrieve all the documents containing both of these terms. The use of AND limits the search or makes it smaller.
- Boolean - OR queries
Doing a Boolean search with the operator OR will broaden the search or make the search larger. The documents will contain either the words reptiles OR snakes OR lizards, but not necessarily all. So, the use of OR greatly increases the number of documents you will retrieve.
- Boolean - NOT queries
Another type of Boolean searching tool is the NOT operator which allows you to exclude words from the search. If a document has a word that you would like to search but that document also contains another word that you do not want to retrieve, then it will exclude that document from your search query results. The query reptiles AND snakes NOT lizards will find all the documents containing the words reptiles and snakes, and exclude the documents containing the word lizards. The use of NOT limits your retrieval.
There are many other Boolean operators, but these are the basic ones to help you get started with your searching.
As a reminder, if you are finding too much information and too many sources, narrow your topic by using the AND operator:
college AND students AND health AND drugs
Finding too little information may indicate that you need to broaden your topic. For example, look for information on students, rather than college students. Link synonymous search terms with OR:
drugs or cocaine or pcp or crack.
How do you decide which search engine to use when searching the Web? There are a variety of different search engines to choose from depending on your information need. Whichever search engine you choose, it is important to keep in mind that the Web is fluid, and what you find on day may not be there the next. If the source is from a reputable organization, it is more likely that the information will be consistently available.
No search engine searches the entire Web. After all, there are billions of pages available online. The largest search engines, Google, Yahoo, and Bing, search the most Web content. The reasons for the differences in pages searched are complicated; they have to do with the way the engines search and the way content is indexed.
To help you decide which search engine to use, review Which Search Engine When? for a description of the features of the different types of search engines.
Try your search terms in several different engines and look at the sources you retrieve and the way they are displayed. You will develop a few favorites once you experiment with them. Remember that no one search engine searches the entire Web, and it is a good idea to use two or three search engines for your search.