LOGARITHMS: Their use in information theory
Charles François (2004). LOGARITHMS: Their use in information theory, International Encyclopedia of Systems and Cybernetics, 2(1): 1941.
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1941 ▶ |
| Object type | Discipline oriented |
Dual logarithms (i.e. to base 2) are a measure of the number of binary decisions (BITS = binary digits) needed to suppress uncertainty in a situation.
Log$_{2}$N also measures ASHBY's variety, as indicating the number of succesive choices to be made in order to obtain a precise distinction. ASHBY gives the following example: “What is the variety in bits of the 26 letters of the alphabet?” The reply is 4,7 bits. i.e. in practice 5 succesive choices to be made to completely determine the position of one specified letter within the English alphabet, using yes or no answers to questions like: Is it in the first half of the alphabet? Is it in the 2nd half of the first half?, etc.