Lecture 4 - HCMT ( T/F )

Boolean Logic

• Boolean logic is a type of search syntax that helps users conduct better, more exact searches.
• It involves using the Boolean operators: AND, OR, and NOT to link words and phrases for more precise queries.
• Boolean logic is used when searching using more than one keyword or phrase.

Boolean Operators

• AND: Narrows the search by retrieving only documents that contain every one of the keywords entered.
  • Example: truth AND justice
• OR: Expands the search by returning documents in which either or both keywords appear.
  • Example: college OR university
• NOT: Limits the search by excluding certain keywords.
  • Example: cloning NOT sheep

Using Boolean Operators

• Use parentheses to separate keywords when using more than one operator and three or more keywords.
• Use "+" and "-" symbols in place of AND and NOT operators.
• Use double quotation marks (" ") around two or more words to force them to be searched as a phrase in that exact order.

Things to Consider

• Different databases and search engines handle Boolean operators differently.
• You may have to select "Boolean search" or "Exact phrase" options.
• Some databases may only allow full Boolean operators in the advanced search option.

Wildcards and Truncation

• Use wildcards (*) to substitute symbols for certain letters in a word.
• Use truncation to look for variations in spelling and word form.
• Examples: colo*r, dog and dogs, give and giving.

Boolean Logic Origins

• Boolean logic takes its name from British mathematician George Boole (1815-1864).
• Boole wrote about a system of logic designed to produce better search results by formulating precise queries.
• He called it the "calculus of thought".