Information, what is it, then?

[Dabljuh]

This question has haunted me for a year now. What is information? I mean, we can measure it, we can use it, we can cuddle it, but I do not know of a sensible definition of what the universal phenomenon that which we call "information" is.

So far I have only come up with one important aspect of it: Time. Or causality. Without either (they are related) information would be impossible.

So I'm asking you. Maybe one of you has stumbled across a good definition. What is Information?

 

[fuelair]

That which I need or want to know or which I am presented with helter skelter is information. Any input not previously input or input in a different way that impacts its' importance or utility.

 

[JoeTheJuggler]

There are a number of different definitions of the word information. What exactly are you after? I don't follow how time and causality are aspects of information.

Have you checked out any dictionary definitions to see if they'll help? They define it with ideas like knowledge, intelligence, data or the communication or reception of communication thereof.

 

[l0rca]

Information is a form of qualia.

We have no idea what qualia is.

Ha ha.

 

[Nick Bogaerts]

Since this is in the Science and Mathematics and not the Philosophy section, I'll give the best definition of information I've come across:

Information is a measure of the decrease in uncertainity (entropy) after reception of a message.

If you are mathematically enclined, I suggest Shannon's seminal 1948 paper, A Mathematical Theory of Communication

 

[catbasket]

Trying to paraphrase someone who once attempted to teach me -

A big bucket of numbers is data. The same numbers organised in some way, e.g. tables or spreadsheets, is information.

I could be wrong.

 

[Dymanic]

Information is a measure of the decrease in uncertainity (entropy) after reception of a message.

The existence of a communications channel, with a sender on one end and a reciever on the other, is assumed under Shannon. Within those parameters, information can be crisply defined. Treating the initial (and tacit) assumptions as though they were universally applicable leads to absurdities. Footprints in snow might be treated as information, but does treating them as such instantly transform the snowfield into a "communications channel"?

 

[Gord_in_Toronto]

Trying to paraphrase someone who once attempted to teach me -

A big bucket of numbers is data. The same numbers organised in some way, e.g. tables or spreadsheets, is information.

I could be wrong.

This is similar to the definition used in IT -- information is organized data.

YMMV.

 

[Schneibster]

I was going to go to Shannon information but Nick beat me there. It's the best technical definition I know of.

 

[fuelair]

Since this is in the Science and Mathematics and not the Philosophy section, I'll give the best definition of information I've come across:

Information is a measure of the decrease in uncertainity (entropy) after reception of a message.

If you are mathematically enclined, I suggest Shannon's seminal 1948 paper, A Mathematical Theory of Communication

I like mine (well, I would) but this is not bad at all and adds to it (especially as a sub part of my second sentence.)

 

[Ginarley]

Russell Ackoff's description which discusses a hierarchy from data to wisdom (including information) is the best I have seen. A good explanation is available here: http://www.systems-thinking.org/dikw/dikw.htm

 

[Puppycow]

Gregory Bateson defined information as "a difference that makes a difference".

Hold your hand perfectly still, palm upwards and resting comfortably on a table. With your other hand, drop a small coin into the palm. You will feel the impact, and if the coin is cold, you will feel the coldness of the metal. Soon however, you will feel nothing. The nerve cells don't bother repeating themselves. They will only report to the brain when something changes. Information is difference.

A lizard hunting insects operates on the same principle. The lizard's eye only reports movement to the lizard's brain. If the hunted insect settles on a leaf, the lizard literally cannot see it. But the moment the insect starts to move, whop, the lizard can see it again, and the tongue flickers out and catches it.

But there are differences and differences. Information is difference that makes a difference. You were probably aware, as you dropped the coin into your palm, your eyes told you automatically, without your brain even asking, what the value of the coin was; but you were probably not aware what date it was minted. This is because (unless you are a numismatist) the value of the coin makes a difference to you whereas its date doesn't.

What is it that makes a difference to a lizard, to a numismatist, to you? Surely not the same things. What is information for the lizard is not information for you, and what is information for you is not information for the lizard.

This is why the perspective of information is important. Perspective defines what counts as information at all, perspective defines to whom the information makes a difference.

(In other words, only someone who understands Chinese can glean any useful information out of it).

 

[Dymanic]

Information is difference that makes a difference.

Perspective defines what counts as information at all, perspective defines to whom the information makes a difference.

Though phrased differently, this is pretty much what fuelair said above while introducing what I find to be the critical term: utility. Information (in the "universal" sense the OP craves) can be anything, but only within the context of some kind of goal. Where needs and wants are absent, so is perspective.

 

[JoeTheJuggler]

So far I have only come up with one important aspect of it: Time. Or causality. Without either (they are related) information would be impossible.

I don't get what you're after, or how this is meaningful.

Is there any term you can put in for x where this statement is NOT true?

"Time. Or causality. Without either (they are related) x would be impossible."

 

[Soapy Sam]

At one level, all information is a mechanical process.

A key fits a lock. We might say the information required to open the lock is encoded in the key- but if the lock no longer exists, while the key does exist, does the information exist?

I should say not.

The same holds for other information storage media.
A floppy disc is all but useless these days.
A DVD is just a diffraction grating without a dvd player.
Semen is just goop without a womb.

Information is coded interaction.

The course of a flung rock might require a dvd to store the spacetime coordinates in detail, but the course exists independent of information. It's really there. spacetime.
Does the universe become richer in information, every time a rock falls?
I doubt it.

I think "information" is like " number" another of the abstract concepts human brains find useful, but which have no actual existence outwith human referents.

*Dons tin hat and crawls under table*

 

[Cuddles]

A key fits a lock. We might say the information required to open the lock is encoded in the key- but if the lock no longer exists, while the key does exist, does the information exist?

Yes. Information about what the lock was like.

The same holds for other information storage media.
A floppy disc is all but useless these days.
A DVD is just a diffraction grating without a dvd player.
Semen is just goop without a womb.

They still all contain information, in the same way that a sentence in Chinese contains information, even though I can't read it. What is important is not that the information can be decoded by a particular person in a particular place, it is that it is possible to decode it.

This does raise the question of when does information stop being there? In 1000 years a floppy disc will not be capable to being read and the key to decoding it will be gone. For all intents and purposes it no longer contains information because no-one can read it. However, as long as you know what a lock is, a key contains information even if the specific lock it opens does not exist.

 

[Soapy Sam]

It only tells you what the lock was like if you already know what keys are for- ie if the context of your background knowledge includes locks and keys. If information is "real" in the sense of an actual , measurable thing , as opposed to a human neural / cultural construct, then it should be discernable and measurable by any intelligence (and perhaps by other things), whether or not there is a shared culture.
I grant you that a dvd found in space by aliens would probably convey the information that it was an artifact (shades of Paley) given that said aliens had senses and intelligence in some way mappable onto ours. They might even deduce that it was a record. They might even manage to play it.
Hell, they might even understand what they saw.
But that just means certain light patterns can interact with suitable other things, like nervous systems, to alter the chemistry thereof.
Where is the " information" in this process?

I could alter alien neurochemistry by belting him/her/it over the head/ braincase/whatever, with a rock. Was the information stored in the rock?
That's what I'm getting at. Information is context dependent. There is a wealth of knowledge among humans about keys and locks. To a cyborg from planet X there is no information in the key about the original lock.

I'm far from confident that a DVD contains information if no dvd player exists.
It contains a series of holes. Those holes only contain meaning in the appropriate context, which is a dvd player. Even then, they only contain meaning when viewed by a human. What is the meaning of information if it is not in a human head.

 

[Dave1001]

Since this is in the Science and Mathematics and not the Philosophy section, I'll give the best definition of information I've come across:

Information is a measure of the decrease in uncertainity (entropy) after reception of a message.

If you are mathematically enclined, I suggest Shannon's seminal 1948 paper, A Mathematical Theory of Communication

that makes sense, perhaps minus the "reception of a message". I think a good starting point for a definition of information from a solipsistic point of view is reduction of apparent uncertainty about apparent reality. An more objective definition of information might be reduction of homogeneity (entropy) in a subsection of apparent reality.

 

[Dymanic]

Information is coded interaction.

I agree. But not all interaction is "coded". The path taken by a rolling rock is influenced by the topography of the hill, but because the influence is exerted directly, there is no coding/decoding, hence, no information.

What is important is not that the information can be decoded by a particular person in a particular place, it is that it is possible to decode it.

If that is what is important, it derives its importance from what it assumes: the existence of an agent possessing both the ability to perform the decoding and some reason for doing so.

 

[Nick Bogaerts]

The existence of a communications channel, with a sender on one end and a reciever on the other, is assumed under Shannon. Within those parameters, information can be crisply defined. Treating the initial (and tacit) assumptions as though they were universally applicable leads to absurdities. Footprints in snow might be treated as information, but does treating them as such instantly transform the snowfield into a "communications channel"?

I would say yes, it could make sense to treat the snowfield as a communication channel, and the snow itself as a two-dimensional signal (the snow depth being the amplitude). That this mathematical model is adequate or not depends very much on what you want to do with it. This example is not too far removed from digital watermarking, where you wish to transmit information (a watermark) through a noisy channel (an image).