Two of the most important aspects of a comprehensive literature search are to:
You make your search comprehensive by thinking through what you need to know and planning which databases and search terms you need to use to get your answer. You make the search reproducible by carefully documenting all the databases and search terms you used, whether you altered the search at all or decided to exclude certain items, and the items collected.
Below are recommended databases and links to articles that describe the process of doing a comprehensive literature search.
Keywords are words that carry content and meaning. The keywords in the research question "What is the feeding range of the blue whale in the Pacific Ocean?" are feeding range, blue whale and Pacific Ocean.
Think of words similar to your keywords in case a database doesn't use your original keywords. Synonyms for blue whale are baleen whale and Balaenoptera musculus.
A Boolean search is a search using the words AND, OR and NOT between the keywords. These words have a special function when used in a database.
You can avoid doing multiple searches for variations on word endings using the truncation symbol * (the asterisk) in most databases. Entering the keyword "blue whale*" will look for both blue whale and blue whales.
If you want a literature review, add "AND review" to your keywords. To find a research study, add "AND study" to your keywords.
Always go to the Advanced Search in a database to enter your Boolean searches because it gives you multiple boxes with the Boolean operators between them. If you are using a search with multiple search strings, enter OR within the search boxes and AND between the search boxes, e.g., [blue whale OR Balaenoptera musculus] AND [feeding range OR feeding grounds] AND [Pacific Ocean].
Many instructors require you to use peer-reviewed sources for your papers and projects, but what does that mean?
Most databases allow you to limit your search to peer-reviewed articles. Here are two examples:
When you don't know synonyms for your topic keywords, you can use science dictionaries and encyclopedias to find them. The UNT Libraries have numerous online reference books you can use.