Exformation

Exformation is a term meaning explicitly discarded information. It was coined by Danish physicist Tor Nørretranders in his book The User Illusion published in English 1998. Originally spelt eksformation in Danish, the word first appeared in English in an article^{[citation needed]} Nørretranders wrote in 1992.

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Meaning

Effective communication depends on a shared body of knowledge between the persons communicating. In using words, sounds and gestures the speaker has deliberately thrown away a huge body of information, though it remains implied. This shared context is called exformation.

Exformation is everything we do not actually say but have in our heads, when or before we say anything at all whereas information is the measurable, demonstrable utterance we actually come out with.

If someone is talking about cows, for example, what is said will be unintelligible unless the person listening has some prior idea what a cow is, what it is good for, and in what context one might encounter one. From the information content of a message alone, there is no way of measuring how much exformation it contains.

In 1862 the author Victor Hugo wrote to his publisher asking how his most recent book, Les Misérables, was getting on. Hugo just wrote “?” in his message, to which his publisher replied “!”, to indicate it was selling well. This exchange of messages would have no meaning to a third party because the shared context is unique to those taking part in it. The amount of information (a single character) was extremely small, and yet because of exformation a meaning is clearly conveyed.

Thought, argues Nørretranders, is in fact a process of chucking away information, and it is this detritus (happily labelled exformation) that is crucially involved in automatic behaviours of expertise (riding a bicycle, playing the piano), and which is therefore the most precious to us as people.

—The Guardian, September 1998

See also

• Shannon–Hartley theorem
• Code rate
• Redundancy
• Channel capacity
• Systems theory
• Negentropy
• Complex systems
• /dev/null