The Analog/Digital distinction: a communication fundamental

1) There are three definitions for the use of the terms “analog/digital”

a. Mathematical communication theory (Shannon, Weaver) defines them as synonyms for continuous v.s. discrete.

b. Cognitive science (Minsky, Dennett,) uses the term “analog thinking” to describe the mental use of analogies.

c. Cybernetics (Wiener, Bateson) uses the distinction as two different forms of representation.

2) The cybernetic definition:

a. Digital: “There is nothing ‘sevenish’ about the numeral seven” (Bateson). Digital representation makes use of physically arbitrary symbols. That is, the physical structure of the symbol is chosen by social convention.

b. Analog: The physical structure IS the information – that is, an analog signal changes in proportion to the information it represents. The gas gauge on my car, the loudness of my voice, the mercury in a thermometer.

3) The cybernetic definition is often in conflict with the information theory definition:

a. Cursive handwriting can be continuous between letters and even words; from a cybernetic view it is still digital (arbitrary signifiers).

b. The loudness of my voice is discrete (there are breaks between words); from a cybernetic view it is still analog (increase in loudness is proportionate to change in emotional information).

4) The cybernetic definition is often in conflict with the information theory definition: I can make an analogy using either analog or digital representation.

5) The cybernetic definition implies that all 6 sensory modalities are capable of both analog and digital representations. Vision, for example, can accept both writing (digital) and pictures (analog).

6) The analog/digital difference is a spectrum. Icons are in the middle (both pictures and words). It is dynamic – a picture can become an icon over time, and an icon can become an arbitrary symbol.