Relevance is a term used to describe how pertinent, connected, or applicable something is to a given matter. A thing is relevant if it serves as a means to a given purpose. Imagine a patient suffering a well-defined disease such as scurvy caused by lack of vitamin C. The relevant medical treatment for him would be doses of tablets containing vitamin C (ascorbic acid). Other medicines, such as vitamin B, are non-relevant. Given this example, we can generalize and have the following Definition: Something (A) is relevant to a task (T) if it increases the likelihood of accomplishing the goal (G), which is implied by T. (Hjørland & Sejer Christensen,2002). A thing might be relevant, a document or a piece of information may be relevant. The basic understanding of relevance does not depend on whether we speak of "things" or "information". What is relevant in relation to a given question depends on theory or "paradigm". If you believe that schizophrenia is caused by bad communication between...