Learn how to identify keywords, brainstorm search terms, and utilize search tools such as controlled vocabulary, phrases, Boolean Operators, and truncation to construct expert searches that will save you time and energy.
Keywords (also called search terms) are words that describe or relate to your research topic. Choosing the best keywords can be difficult. The easiest way to identify effective keywords is to brainstorm:
- Main points of your topic
- Synonyms for those main points
|How should college athletes be compensated?||College athletes, student athletes, compensation, NCAA, “Fair Pay to Play Act”|
|Starting a business in Afghanistan||Afghanistan, business, “foreign investment,” labor, entrepreneurship, “market forces”|
|How should Creationism be addressed in the science classroom?||Creationism, “intelligent design,” evolution, teaching, instruction, “curriculum policy,” law, “state standards”|
Database vendors evaluate each journal article and book for key concepts and then assign standardized terms called controlled vocabulary. Controlled vocabulary can also be called subjects or descriptors, which varies database to database. Controlled vocabulary terms are standardized and controlled, so they may not be phrases you would think of off the top of your head. See examples below.
POST-traumatic stress disorder — Treatment
BUSINESS enterprises — United States
WORKSHOPS (Adult education)
When you search for a resource using controlled vocabulary terms, you will retrieve relevant, topic-specific results. You will see fewer irrelevant or useless results.
Consider the word target. Do I mean:
- Target, our locally-headquartered mega-store?
- A target as in a bull’s-eye?
- Medically, as in a targeted body part?
When you use controlled vocabulary, you can give context to your database search. By using the database’s controlled vocabulary, the database (in this example, EBSCO MegaFILE) immediately knows the meaning and context of the word “target.”
In order for a controlled vocabulary search to be successful, you need to know where to locate the correct vocabulary term for your topic. Location varies from database to database.
On the search results page, controlled vocabulary appears automatically under each article title and in the left column under “Subjects.” See example .
On your results page, controlled vocabulary appears above your search results and in the lower right column, under headings including “Subject,” “Company/organization,” and “Person.” See example.
PubMed | MedLine
PubMed uses Medical Subject Headings, or MeSH. Learn how to search using MeSH.
Databases do not recognize context. They understand words as individual, unrelated items. (Think hot dog.) Therefore, if you search with a phrase, put quotation marks around it! Quotation marks force the database to search for the phrase as a whole, not just the words here and there. See comparison.
Placing AND between two or more keywords tells a database to retrieve only results including all of the keywords you enter. This narrows your search and increases the relevancy of your search results. See example. Most search engines do this automatically.
Placing OR between search terms is a great way to search for synonyms of words. OR broadens your search, allowing the database to find just one of the search terms. See example. Use the operator OR in conjunction with an AND search. Use the different search boxes or parentheses to distinguish between the two parts of your search – otherwise the database doesn’t know which words to read with AND and which words to read with OR (think of a math equation). See example. Most search engines’ equivalent: OR (in capital letters)
Placing NOT before a search term excludes that specific term from your search results. See example. Most search engines’ equivalent: – (minus sign, hyphen)
Another way to expand your search is to truncate it. Truncation locates multiple forms of a word, including different endings. By adding an asterisks (*) to the end of a root word, search results will include any applicable variation of the search term. See example. Most search engines do this automatically.
Limiting your search to specific database fields can results in more relevant results. In most databases, searchable fields include:
- Title (article or book)
- Journal name
Example: If you are looking for books by Barack Obama instead of about him, you should limit your search of his name to the author field (and to book as resource type!). See example.
If you do not choose a specific field, the database usually defaults to a keyword search, where your words will be searched anywhere in the item record.
Subject-specific databases have specialized fields unique to the field of study. These fields might include Subject or Descriptors (controlled vocabulary), Geographical Location, Company Name, ISBN, Population, Methodology, DOI, Language, Educational Level, or NAICS Code, to name a few.