BIOL 3764 - Careers in Microbiology: Search Strategies

A Bit of History

Boolean operators are named for George Boole (1815-1864), an English Mathematician and Philosopher.  Boolean Algebra and Symbolic Logic both derive from his work.  Boole is generally considered the father of modern computer science.  Most electronic indexes (databases) require the use of Boolean operators in parsing search terms, although this is not always apparent.  Boolean search statements are incredibly powerful in retrieving what you need provided 1) the statement is formatted correctly and 2) your choice of search terms is correct for the topic you are researching.  

Boolean Searching

Rather than typing a full sentence or question into a search box, using Boolean operators can help you create an efficient and effective database search.

Try the Search Strategy Builder, which will create searches out of keywords that you supply!

Example search statements using Boolean operators and symbols:


Rhodococcus fascians

Rhodococcus fascians AND pistachio* AND "bushy top syndrome"

(Rhodococcus fascians OR Corynebacterium fascians) AND (pistachio*) AND ("bushy top syndrome" OR "leafy gall syndrome")

(Rhodococcus fascians OR Corynebacterium fascians) AND (pistachio* OR "pistacia vera") AND ("bushy top syndrome" OR "leafy gall syndrome")

           (Calcium AND milk) NOT goat

            child* AND anxiety AND (exercise OR "physical activity")

Boolean operators

  • AND:  both terms that you connect with AND msut be somehwere in the bibliographic record for that record to be retrieved.  AND narrows a search and retrieves fewer articles
  • OR:  only one of the search terms combined with OR is required for the bibliographic record t5o be retrieved.  OR broadens a search and retrieves more articles
  • NOT:  excludes a particular subset, category, or term.  NOT requires the presence of one search term and the exclusion of another.

Read more about Boolean searching here: 

Truncation:  A symbol, specific to the search interface, which allows the retrieval of all endings for the specified base word. An asterisk (*) isoften used.  For example, child* would retrieve records with children, childish, and every other word that begins with the root word "child."  

Wildcard:  A symbol, specific to the search interface, which allows the retrieval of various spellings of a word. A questio mark is often used.  For example, wom?n would retrieve records with women or woman.  

Phrase Searching: Adding quotation marks around a phrase, such as "bushy top syndrome" will tell the database to search for these words together, rather than separately. *This will narrow your search (get you less results), so keep that in mind, but in some cases it's the best way to find results with a specific phrase of interest - especially when the words in that phrase are common on their own (like physical and activity).

Read more about these sorts of tricks here:

Biological Sciences Liaison

Profile Photo
Amanda MacDonald
560 Drillfield Drive
Blacksburg, VA 24061
Office: Newman Library 3043