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BIOL 5098-01: Graduate Seminar (Heilveil) Fall 2023



Before doing any research, it is important to know what words you will use to search for books and articles.  Choosing the right words and search strategies can make all the difference, and it's important to remember that research is an exploratory process.  It is rare to find exactly what you are looking for on the very first try. It is a process that usually requires multiple searches using multiple keywords or subject terms. 

Keywords, also called search terms, are words you enter into a database or search engine to find relevant sources on your topic. The keywords represent the core concepts of your research question or topic. It may take multiple tries to find the keywords that bring you to relevant sources.

Keywords ("any field" or "select a field") will search titles, subjects, tables of contents, and descriptions. 

Subject terms are standardized and will give you better, more specific results, and will only search subject.  To find subject terms for books, use the Library of Congress Subject Headings.  These will also give you narrower and broader terms.  Some databases have a thesaurus or index that provide subject terms.


To get ideas for additional search terms, try the following:

  • Identify the main concepts of your topic
  • Brainstorm synonyms, larger concepts, and narrower concepts
  • Spell out abbreviations
  • Check out background sources such as encyclopedias for additional terms
  • Look at the list of subject terms when you locate an article using the library's databases
  • Look through online and print subject encyclopedias to identify relevant terms, issues, and research

Boolean Operators


Boolean operators are words or symbols that are used in conjunction with words to refine searches. They can typically be used across most platforms, including specific databases like Academic Search Complete and Milne Search. Listed below are six common Boolean operators.


AND - narrows 

Ex: streams AND ecology (this narrows down our results to include only results with both streams AND ecology in the record) 


NOT - excludes

Ex: "fish parasitology" NOT saltwater (this narrows down our results to include items about fish parasitology, excluding those that mention saltwater) 


OR - expands

Ex: stream OR river (this expands to search for multiple possible terms) 


* - expands 

Ex: parasit* (Asterisks are called wildcards. They expand a search by finding words that start with the same letters. In the example here, the search results would include such words as parasite, parasites, parasitology, etc.)


"      " - exact phrase

Ex: "population modeling" (this pulls up results that are stated in the item exactly as written) 


(   ) - confines

Ex: (stream OR river) AND ecology     

(this will instruct the database or search engine on what parts go together in your search phrase)




Example of using boolean operators. 

Adding a search field

A search field tells the database where to look for the keyword in the sources it will include in the search results. Search fields include "author," "abstract," "subject term," "title," or "full text." 

A abstract is the summary of the article and explains what the article will cover. 

A subject term is a descriptive word assignment to an item to denote the item's subject or main themes.