Hehs: Boolean Search
What is a Boolean Search?
Boolean searching is built on a method of symbolic logic developed by George Boole, a 19th century English mathematician.
A Boolean search allows users to combine words and phrases with operators such as AND, OR and NOT (known as Boolean operators) to limit, broaden, or define the results of a search.
An effective Boolean search requires the following:
Keywords, Guided Keywords, or Subject Headings
Use the appropriate Boolean operators or modifiers to enhance results
Know the limits of the database being searched and look under help or tips for fine tuning of a particular product
George Boole, (born November 2, 1815, Lincoln, Lincolnshire, England—died December 8, 1864, Ballintemple, County Cork, Ireland), English mathematician who helped establish modern symbolic logic and whose algebra of logic, now called Boolean algebra, is basic to the design of digital computer circuits. (Britannica.com)
Keywords for Searching
A KEYWORD search looks for words (of importance/relevance) anywhere in a record. A KEYWORD search can be of benefit when you are uncertain of what kind of SUBJECT search you can run because of a lack of information about a new topic. However, KEYWORD searches can return a large number of results so it may become necessary to narrow or refine your search. A GUIDED KEYWORD search is a combination of terms or fields to be searched.
How can we strive to make space travel more ergonomic and economical?
"space travel" - spaceflight, rockets, spacecraft, astronautics
"ergonomic" - comfortable, functional, convenient, livable
"economical" - affordable, low-budget, reasonable, efficient
University of Colorado Boulder Libraries
SUBJECT searches must use terms as they are found in the Library of Congress Subject Headings (LCSH) list or the National Library of Medicine's Medical Subject Headings (MeSH) list. SUBJECT searches will use a 'left-hand' truncation, so you'll only need the beginning of a subject heading to find all related search terms.
Library of Congress Subject Headings
(found in middle of page with Individual PDF files by A-Z)
National Library of Medicine's
Medical Subject Headings
(found under an online MeSH browser linked to headings)
Developing a Search Strategy
There are a variety of strategies that you can use when looking for information. When starting your search, it is important to plan out your search strategy in advance, and use the following steps as a guide.
1. Define your Topic : a few sentences that easily explain what you want to explore and why it is of interest to you.
2. Choose keywords: take your topic sentences and pull keywords to align your search strategy to your topic and goals.
3. Group keywords: together for a more effective and relevant search response.
4. Deduce relationships between keywords and be ready to include synonyms and like terms for possible "expansion / explosion".
Hints, Tips and Tricks
Decide which groups of keywords are essential - start with those
Don't neglect to include singular/plural forms, alternative words, British spelling.
Build your search strategy in small, logical steps.
Experiment with short phrase searching after trying a keyword.
Try this worksheet to coalesce your thoughts into a search strategy.
Types of Boolean Operators
OR: The OR keyword tells the search to look for instances with either of the phrases entered.
For example, searching for gardeners who have worked with "Fescue" OR "Bermuda" in lawns.
AND: The AND keyword tells the search to look for instances with both phrases entered.
For example, searching for hotels who have "customer service" AND "hospitality" in their profile.
NOT: The NOT keywords tell the search to exclude certain text from the search.
For example, searching for hotels who "Tobago" AND "beach" AND "ocean" NOT "pool" in their profile.
Boolean Modifiers
Quotation Marks: Use quotation marks to enclose phrases.
For example, typing President of Ghana will return an error because the search phrases (President and Ghana ) are not recognized as having been connected. You will get information about the job of President or the President of a local bank mixed into geography and maps of Ghana. "President of Ghana" relates the terms and identifies a particular person.
Parentheses / Phrase: Use parentheses to combine parts of a complex search equation.
For example, searching for employees who know "HTML" OR ("Java" AND NOT "JavaScript") in their resume. As in mathematics, items enclosed within parentheses are searched for first.
Asterisk / Wildcard: The asterisk (*) serves as a wild card character. To find a term with variant spelling or endings, use a question mark (?) as a wildcard or truncation symbol. This can be helpful with the British/American spelling differences on the same word.
For example, typing in "wom*n" will return results with woman or women.
For example, typing in "link?" will return instances of link, linking, linked, etc.; while "col*r" will show results with color or colour.
Double Asterisks: Double asterisks (**) allow searching for all forms of a word.
For example, typing in "sell**" will return all instances of sell, sold, selling, etc.
Straight from the Horse's Mouth . . .
Handouts, Cheats and Tips
Top-Five-Searching-Strategies-Handout.pdf