Take you research question or thesis / topic sentence, and highlight only the words that are crucial to expressing your search topic:

Example:

Is it better to manage chronic childhood asthma with a mist inhaler or a powder inhaler?

becomes

Is it better to manage chronic childhood asthma with a mist inhaler or a powder inhaler?

So you end up with:

manage

chronic

childhood

asthma

mist inhaler

powder inhaler

These are your initial keywords - you need them to tell the database search engine what has to be in the articles it brings you.

 Once you start searching, you're likely to see synonyms and related words in the results that may also make good keywords to use.

Identify good keywords to use in your search by thinking about the main ideas inherent in your topic.

Consider using synonyms of your keywords to help find even more information. For example, if you are looking for articles about the benefits of a womens college, you might use the keywords and synonyms below:

Keyowords:  women       education     benefit

Synonyms 1:   single sex    college   advantage

Synonyms 2:   female    school   leverage