What is Boolean Search?

AbeBooks’ Boolean search allows you to perform very specific searches. It’s based on a mathematical logic but is actually simple to use. Boolean logic helps you to expand or restrict your search. Boolean has three so-called operators (commands to our search engine) – AND, OR and NOT.

NOT is given the highest precedence in Boolean, followed by AND, and then OR. If you have two Boolean operators in one search, the search will use the order of precedence.

  • Boolean Search as only available from the Advanced Search screen.
  • Always remember to turn Boolean on first by clicking the radio button.
  • Any Boolean operator must have a term both before and after. Forgetting one or the other is the most common error. For instance, after putting Stephenie Meyer into the author field, a valid Boolean title search would be – Twilight NOT New Moon. An invalid Boolean title search would be – NOT New Moon.
  • Be aware quotation marks around search terms will indicate an exact phrase and ensure even stricter searching. The terms entered will be matched exactly. This can be good or bad. An “Ernest Hemingway” author search will return only books where the author field contains exactly that, and will not include any books where the author is listed as Hemingway, Ernest.
  • The keyword field is extremely useful for Boolean searching because it searches all fields for data (author, title, publisher, description etc). For example, a keyword search for Stephen King NOT The Stand will return all books by or about Stephen King except The Stand, which will be excluded.

Examples of Boolean Searches:

Example 1 – Exclude ex-library copies using the NOT operator.
Enter a positive term(s) into the keyword field, followed by the NOT operator(s) and term(s): J.R.R Tolkien, The Hobbit NOT ex-library NOT ex-libris

Example 2 – Exclude a certain publisher using the NOT operator.
Enter a positive term into publisher field, followed by the NOT operator and term: Bloomsbury NOT Scholastic

Example 3 – Find two books with one search using the OR operator.
Complete the author field (eg Ian McEwan) and then complete the title field, separating each term with the OR operator: Atonement OR Amsterdam. Two separate searches will occur but your results will combine both sets of results.

Example 4 – Expand a search with multiple OR operators.
You want books about war. Enter into keyword field: war OR military OR battle OR warfare OR combat

Notes:

  1. Be careful when using Boolean and searching for titles/keywords containing ‘and’, ‘or’ & ‘not’. For instance, searching for Hemingway’s famous books, To Have And Have Not and The Old Man And The Sea, can cause problems, as Boolean will recognize the operator words (and, not) contained within the titles. Avoid this problem by putting the titles in quotation marks – “To Have And Have Not” OR “The Old Man And the Sea”. Your search will include both titles in a combined set of results.
  2. To group a series of words together, use parentheses to string a series of terms together and properly categorize your results. For example, a keyword search of (Khaled Hosseini NOT “A Thousand Splendid Suns”) OR (Ernest Hemingway NOT “Old Man and the Sea”). Parentheses can also be used to force the order of processing.

Invalid Boolean Searches

  • Keyword search (lacks negative term): Cat not
  • Author search (cannot have successive operators without a search term): Stephen or not King
  • Title search (lacks positive term): not The Shining