Earlier we proposed a hypothetical search; the use of therapy dogs and cats in nursing homes in America.

[While a list of index terms for this search may include other or even more words than will be demonstrated here (such as canine, feline, or other words or synonyms), we'll stick with this short list of words to show you how we organize our search terms effectively.]

What would that search look like once we selected a database and entered our search terms? It could be organized many ways, but in order to achieve the best results we need to focus on how we group our search terms in relation to the Boolean Operators we use.

The database takes the first combination of terms and Boolean operator and creates a new results set. That set becomes the basis of our next search term and command, and so on. This means that we must group our search sets so that we either narrow or expand the CORRECT article sets.

Let's look at that nursing home search. Here's how we would want to do this search:

cat and dog (set 1)

(cat and dog) and therapy animals (set 2)

((cat and dog) and therapy animals) and nursing homes (set 3)

(((cat and dog) and therapy animals) and nursing homes) and (United States or America) (set 4)

That last line shows you how the computer would read the search and build upon a previous set to get the final list of journals related to your search terms that you had hoped to obtain. It might help, perhaps, to think of a pyramid. You begin your search at the bottom of the pyramid -- the largest set. You narrow the focus of your search as you climb to the top of the pyramid (using the Boolean command AND). Each time you add another AND command, you take the base set of results and narrow it -- go up one more rung on your pyramid/ladder -- until you have narrowed your results list down satisfactorily.

Consider how different the above example results list might have been if we had grouped our sets differently:

(((cat and therapy animals) and (dog and nursing homes) and (United States or America)

Even worse:

(((America and cat) or (therapy animals and United States) and nursing homes)

Be very aware of what grouped sets you begin with and subsequently narrow or expand using the Boolean commands. This can have a serious impact on the results you will obtain at the end of your search. It may be useful to think of each set of results as a level on a pyramid. As you continue adding more search terms to your search, you climb up the pyramid. Each level produces a set based on the previous results list and narrowing until you reach the top -- your final set of results. Ask the database for the largest set first. (Butterflies) Narrow the results set by adding more search terms to the second level. (Butterflies and South America). Then use that set as the basis for the next search, narrowing the results list further. ((Butterflies and South America) and Habitat)

Note also that years ago you did need to include the parenthetical groupings. Today, however, the order you enter your sets is the determining factor for how your search terms are grouped. You no longer need to include parens when typing your search into a database search box.

It is also useful to note that while the database will provide you with several lines and options for either drop-down or included Boolean operators, you can type any Boolean command into your search in any box on the search page. This is a very useful feature for a complicated search.

Does this mean that all searches should be complicated and use multiple Boolean operators? No! Use those search terms that will help you get the results you need, including Boolean operators where they will be helpful to you. Always start with the fewest search terms and the simplest search possible. It is very possible that one of your search terms will not return any results at all. Unless you check each term (search a single word or phrase), you won't know which word failed to locate articles. Pearl Gathering -- checking each index word/phrase to verify it will return results -- is a useful way to verify the database you are searching includes articles that contain the information you need. Once you know that there are several articles available for the index terms you selected, you can use the Boolean commands to group your search terms efficiently.

You now have the tools to organize search terms related to the type of information you need to find and to help you narrow the list down to those few articles that will work best for your current research needs. You are now well equipped to begin searching databases (indexed lists of publications) for books and journal articles suitable for your research needs.