Canon of relevance

Canon of relevance Canon of relevance is enunciated thus: “A characteristics used as the basis for the classification of a universe should be relevant to the purpose of the classification”. This definition as given by Ranganathan. Sayers also given the definition for canon of relevance thus: “Each characteristics should be relevant to the purpose of the classification.” The canon of relevance says to used the essential characteristics, essential characterristics means: “Chosen characteristics which is that most useful for the purpose of the scheme, is called the essential characteristic.” EXAMPLE: - 1) Let us take the universe of the boys in a class-room. a) Let the purpose of classification be to divide the boys into convenient graded groups for tutorial work. Then mother tongue, intelligence, and extent of knowledge are relevant characteristics; but height, colour and physical strength are not. b) Let the purpose of classification be to divide the boys into convenient graded groups for physical game. Then height, physical strength and age are relevent characteristics; but colour , extent of knowledge and clothe are not. 2)Let us take the universe of books. a) Let the purpose of classification be to suit the needs of printers. Then typography, leading, margin, illustrations, and paper are relevant characteristics. But subject, author are not relevant characteristics. b) Let the purpose of classification be to suit the needs of the readers in a library. Then subject, langguage, author and year of publication are relevant charecteristics; but the cover of books, the paper used in the books are not. Reference:- Ranganathan,S.R.(1967).Prologomena to library classification.3rd ed.Asia:Bambay. Parkhy,R.S.(1964).Dc &Cc in perspective.Asia:NewDelhi.