What is Truncation? - Librarians Portal

Truncation is the use of a wild card character or symbol to stand for alternate endings attached to a stem word. Truncation is especially useful for retrieving the singular and plural forms of most words.

Example: Library? retrieves

Libraries

Librarian

Librarianship

Lib

Almost all databases support truncation, but they vary in terms of which character is the wild card. The two most common are ? and *, but database help screens always tell you. Whichever character is used by a database, they work the same way.

Be Careful: Be sure you don't truncate too far into a word. For instance pol? retrieves

politics

political

policy

police

polygamy etc.

------------------------------------------------------------------------------------------------------------------------

Boolean Logic, also known as Boolean algebra, is a method for describing a set of objects or ideas. It was invented in the 1800s by George Boolean, an English math teacher, but it is has become part of the foundation for controlling computers. The binary 0 and 1 states are naturally related to the true and false logic variables. By inserting key words, or operators, between terms in a statement you can describe the relationship among the terms.

Operators: You may include the operators AND, OR between terms to define a better search. You can also bracket your terms to clarify the order. For example: 'HOME’ (Home OR quarters OR residence)' will ensure that the term Home is in every resulting document.

OR

Or is a Boolean operator used to broaden your search by retrieving any, some, or all of the keywords used in the search statement. Since the Web is already huge, using OR helps you make sure you aren't missing anything valuable.

OR logic is most commonly used to search for synonymous terms or concepts.

Eg.

Query: College OR University (I would like information about college.)

OR logic collates the results to retrieve all the unique records containing one term, the other, or both. The more terms or concepts we combine in a search with OR logic, the more records we will retrieve.

AND

And is a Boolean operator used to narrow your search by ensuring that all keywords used appear in the search results. Since the Web is already huge, it is important you use AND effectively.

Eg.

Query: I'm interested in the relationship between poverty and crime.

Poverty AND Crime

NOT

Not is a Boolean operator used to eliminate an unwanted concept or word in your search statement.

Eg.

Query: I want to see information about pets, but I want to avoid seeing anything about cats.

Pets NOT Cats

NOT logic excludes records from your search results. Be careful when you use NOT: the term you do want may be present in an important way in documents that also contain the word you wish to avoid.