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Developing an information search strategy: Operators

Simple but efficient actions for a documentalist to assess the latest developments on a topic

Boolean operators OR/AND/NOT

A succession of words does not make a request.

In order to define groups of documents, you need to group them by operator:

  • "OR" for equivalent terms: result -> all documents containing at least one of the terms.
  • "AND" for complementary terms: result -> documents which imperatively contain both terms.
  • "NOT": result -> excludes documents which contain the excluded term.

Other existing operators

There are other operators:

  • right side truncation: it allows you to run a search on a root or to group all declensions of one word. For instance: The request fem* will group all documents containing the terms: female, feminine, femininity, feminists.
  • proximity operators are used to define an element of proximity between two terms.
  • search of the exact phrase or chain of character.

How to phrase your request?

The way to phrase a request varies according to the engine used, each having their own syntax, their own control language.

Request example: energy use cars

  • will bring no result on the Factiva database because all three terms energy use cars will be treated as a chain of characters.
  • will bring over a million documents on Google because they will be treated as 3 terms linked by two Boolean "AND".

To find out the syntax of a database, you need to visit its "help" or "examples" page.

Some databases allow you to record simple requests and to then cross them using the session "history".