Blackwell Reference Online

Extract

1 Any system of symbols used for communicating messages. In information theory the term is used for systems that assign the elements of one sign system to those of another which can thus represent the same information contents. For example, the so-called binary code makes use of only two elements, 0 and 1, which in various combinations can represent the elements of another system, for instance decimal numbers. The combinations 00, 01, 10, 11 can be assigned the numbers 1, 2, 3, 4. The two inventories of signs are then ‘semantically equivalent’. Writing systems are codes which convert audible into visible units of speech. 2 Derived codes are systems of signals used to secure secrecy in conveying a message. The morse code is a derived code which, however, is generally known. It converts alphabetic letters into sequences of dots and dashes. Other derived codes arbitrarily assign code words, code numbers, or other code signs to words, syllables, letters etc. In order to decode the message, the receiver must know the secret code. See also cipher ; writing system . ... log in or subscribe to read full text