Lesson 7 Contents:

Learning Objectives

I. A Brief Review of Basic Keyword Searching

II. Boolean Logic: The use of OR and AND

III. Advanced Keyword Searching

IV. Key Points to Remember

Lesson One Quiz

Lesson One Exercise

III. ADVANCED KEYWORD SEARCHING

Now that you understand the principles of Boolean logic, you are ready to learn advanced keyword searching. Unlike basic keyword searching – in which you search by a single word or phrase – advanced keyword searching requires you to search using a variety of terms that describe each main idea in your research question. This process is very thorough and requires some planning. Given below are 6 steps for preparing and executing an advanced keyword search:

In Lesson 2 you learned how to formulate a research question that’s not too broad or too narrow. Here’s an example of an appropriate research question:

How do pets affect the psychological health of the elderly?

STEP 2: DIVIDE YOUR RESEARCH QUESTION INTO CONCEPTS

Separate your research question into main ideas, or “concepts.” Well-chosen research questions should have 2 or 3 concepts. If you can identify only one concept, your topic is too broad. If you identify more than 4 concepts, it’s probably too narrow. Either flaw would require you to refocus your question.

Each concept should be expressed succinctly in a single word or short phrase of 2-3 words. For example, our question about pet ownership and the elderly can be broken down into 3 concepts:

How do pets affect the psychological health of the elderly?

CONCEPT #1: pets
CONCEPT #2: psychological health
CONCEPT #3: elderly

Given below are more examples of research questions separated into concepts:

Notice that only the most important ideas from your research question are identified as concepts. Therefore, in addition to leaving out the “minor” ideas in your question, you should avoid creating a concept to represent the relationship between concepts. In other words, do not create a concept for notions such as:

effect on
affect of
relationship of
result of
outcome
impact on
etc.

STEP 3: LIST SYNONYMS (OR RELATED TERMS) FOR EACH CONCEPT

Identify synonyms (words that have the same meaning) for each of your concepts. For example, synonyms for the concept “illegal immigrant” include “illegal alien,” “undocumented worker,” and “undocumented alien.”

Listed below are synonyms for each concept in our sample research question:

CONCEPT #1: Pets

• animal companion

CONCEPT #2: psychological health

• mental health
• emotional health
• well-being

CONCEPT #3: elderly

• aged
• seniors
• very old

STEP 4: LINK YOUR SYNONYMS TOGETHER WITH “OR” AND USE TRUNCATION WHEN APPROPRIATE

Use the “OR” logical operator to link together all the synonyms for each of your concepts. By so doing, you are creating a search statement for each of your concepts. Thus, in our example, we now have 3 search statements that correspond to the 3 concepts of our research question:

Search statement #1: pets OR animal companion
(for concept #1)

Search statement #2: psychological health OR mental health OR emotional health OR well-being
(for concept #2)

Search statement #3: elderly OR aged OR seniors OR very old
(for concept #3)

Remember that by placing an OR between terms, you’re instructing the computer to find records containing any one or more of the terms. The more terms you enter for each concept, the broader your search will be.

When you create your search statements, keep in mind that in order to be thorough and retrieve the greatest number of relevant records, you should include different tenses or parts of speech (e.g. “immigration” and “immigrant”) and the singular or plural forms of words (“immigrant” and immigrants”). To simplify the process of searching for variations of search terms, most databases offer a feature called truncation. This feature allows you to type a truncation symbol at the end of a word or word stem. This symbol – usually an asterisk (*) or pound sign (#) -- instructs the computer to find all words that begin with the same set of beginning letters. For example:

child* will retrieve child, children, childhood
teen* will retrieve teen, teens, teenager, teenagers
immigra* will retrieve immigration, immigrate, immigrant, immigrants

Be careful when truncating! If you place the symbol on a short word stem you will retrieve words that you may not want. For example, if you use imm* instead of immigra*, you would retrieve records with the words immerse, immobile, immortal, immovable, etc.

In our example, we would type the following search statements into the database:

Search statement #1: pets OR pet OR animal companion*
(for concept #1)

Search statement #2: psycholog* OR mental health OR emotional health OR well-being
(for concept #2)

Search statement #3: elderly OR aged OR senior* OR very old
(for concept #3)

Notice that truncation is used judiciously. For example, although truncating after “pet” would retrieve the plural form “pets,” we would also get records containing words we don’t want, such as "petulant," "petition," etc. To solve this problem, we simply included both the singular and plural forms of the word “pet” in the search statement.

Note also that the phrase "psychological health" (in search statement #2) has been shortened to simply psycholog*. This use of truncation will pick up single words such as psychology, psychological, as well as phrases such as psychological health, psychological aspects, psychological character, etc.

STEP 5: TYPE YOUR SEARCH STATEMENTS INTO THE DATABASE AND RUN THE SEARCH

Many databases allow you to type your search statements one at a time into a template similar to the one shown here:

Notice that the logical operators at the end of the 1st and 2nd lines are preset to AND. This is the correct setting because you want the computer to find articles that have:

• at least one term from your 1st search statement

AND

• at least one term from your 2nd search statement

AND

• at least one search term from your 3rd search statement.

In Boolean logic, this is known as combining your sets – a set being the group of records that result from a single search statement. Given below is a diagram illustrating what you’re asking the computer to do. The shaded area represents your final number of hits – i.e. those records that contain at least one term from each of your search statements.

STEP 6: REVIEW YOUR RESULTS AND REVISE YOUR SEARCH IF NECESSARY

If your search finds too few records:

• one of your concepts may be limiting your search too much and may have to be excluded

OR

• you might be missing important search terms for one or more concepts

 

If your search finds too many records:

• one or more of your search terms may be too broad

OR

• you may need to focus your search further by adding another search statement corresponding to an additional concept

Finally, if your search is retrieving too many false hits, you should re-examine your concepts and search terms and make sure they accurately and completely cover the main ideas of your research question. You may recall from Lesson 4 that false hits are a common problem when doing keyword searching. This often happens simply because your search terms are being used in a context not relevant to your topic. For example, the term “dating” could pull up articles on radiocarbon dating as well as on relationships. The database does not know which you are interested in.

If you’re having a problem finding relevant records, you may want to contact the librarian who can review your search strategy and suggest other advanced search techniques – such as proximity operators or field searching -- that might be helpful.