A popular misconception is that information and data are interchangeable terms, and that they necessarily involve binary representations. Part of this confusion may arise from the fact that the conventional measurement unit of both data and information is the bit, short for binary digit.
Data (the plural of datum) are recordings of events, in a medium that has the temporal property of 'memory'. Data may be stored, retrieved, transmitted, and/or processed. Let's call these activities 'data use'. Data may be analog or digital, overwhelmingly the latter today because this allows data use without corruption by noise. Binary digital representations are used nearly universally because of conveniences in device engineering, but are not otherwise fundamental.
Here's an example. If I want to represent the outcomes of a dice game, I need to keep track of six different possible states for each die. I will need about 2.6 'bits' of data representation, or about 2.6 factors of two. In binary digital computing, a data bit is embodied in a physical device that is engineered to store just one of two possible states for use. I can't use a fraction of a data bit, so I will need to round up to three data bits to represent six separate states. Two bits can take on four different states (too few), and three bits can take on eight different states (more than enough).
If I am using a decimal representation, like that in a mechanical car odometer, I now have 'decimal digits' or 'decs', which have values from 0 to 9. I will need 0.78 'decs' of data representation to account for six die states, and will need to round up to one whole physical data 'dec' (one whole odometer wheel) to actually do the representational work.
As we will see in part 2 of this posting, measures of information behave rather differently.
The author's affiliation with The MITRE Corporation is provided for identification purposes only, and is not intended to convey or imply MITRE's concurrence with, or support for, the positions, opinions, or viewpoints expressed by the author.
- Jeff's first post on Signals, Sensors and Data and the distinct definitions of the three