The search terms or keywords you use to search are what determine the results you get. Here is an example to help you generate a list of keywords:

Express your topic in a sentence: How does healthy eating affect physical health in children?

Generate keyword search terms by identifying the main ideas or concepts within that sentence: "What is the effect of healthy eating on children?" When you break down your concepts, you end up with Eating, Nutrition, Children, Health, etc.

Expand your search terms by brainstorming related terms or synonyms that describe your main ideas. Keep in mind that word order is not important in a search.

Eating - meals, behavior, environment, food, nutrition

Health - risk factors, longevity, well-being

Children - boys, girls, youngsters, toddlers

Tip: If the database you are using has a Thesaurus, use it to determine which controlled vocabulary words to use. Notice the related, broader, and narrower terms associated with the term you typed in.

You can create complex search strategies by combining keywords using the linking words (or Boolean operators) AND, OR, and NOT. For example, if your search terms are eating and health:

• AND - Narrows and focuses the search results. The search eating and health will bring only results where both terms eating and health are present.
• OR -  Broadens the search results. Using or will bring results where the term eating is present, or results where health is present or results where both terms are present. Or is useful if you have more than one way to refer to a concept. Example: food or nutrition
• NOT - Excludes anything where the term after the NOT is present. Example: children not adults

Searching the root of a word without specifying a particular ending is one way to find variations on a word that relate to the same core concept without searching each word separately.

Some databases automatically search terms for singular, plural, and various other endings.

Some databases use a truncation symbol to indicate that any ending is acceptable after exactly matching the letters entered.

• gene*       will find     gene, genes, genetic, genetics, genetically                                             but not      genome or genomics
• vaccin*    will find    vaccine, vaccines, vaccinate, vaccinated, vaccination, vaccinations

The actual symbol used will vary among databases. The asterisk (*) is most common, but some use a ? or other symbol, so check your database.