This guide explains the principles of "citation": identifying where a website that you are studying (or a book or an article) has been quoted. Special programs and sites have been designed for this type of search.

Listing the "citations" of an article may have several functions:

• It may be an index of the reliability of the site (or article); a text which is often mentioned with praise by other authoritative sources is probably of high quality (see previous chapter on "evaluation").
  
  
• The present guide lists two other purposes:
  • "It is a useful technique for discovering the impact a certain author or piece of work has had on research..." -- if you are researching on the critical reception of a trend of thought
    
    
  • "... or to discover other groups working in the same field as a published piece of research" -- this allows you to expand your list of sources on the subject, not with items published before the text you are reading (as a bibliography would do), but with items published later, which quote it, and which are therefore in the same field.
    
    
    • Moreover, this process helps you to identify, in addition to articles, "research groups" working on your topic -- find out what colleagues and institutions are interested in the same subject. You may then study their websites, attend their conferences... (see later session on "institutional contacts")
      
      
• The guide adds a qualification: "However it must be remembered that citation data is dependent on the authors of the citing paper for its correctrness. Only 10% of published papers are ever cited at all." This might be one answer to the question raised in the tutorial on "evaluation" about the possible limitations of this procedure. Some papers are frequently cited because they originate in influential academic circles in touch with one another; others which are less frequently cited may be of equal value.