Information Theory, Part 2

Wednesday, February 10, 2010

Information Theory vs. Communication Theory

A couple days ago, Svenn started a post inspired by a commenter on another blog he reads (written by a certain controversial goblin). In a continuation of that, today's post will look further at the application of information theory to emergent MMOs, specifically WoW.

Information Theory: Field of mathematics that studies the problems of signal transmission, reception, and processing. It stems from Claude E. Shannon's mathematical methods for measuring the degree of order (nonrandomness) in a signal, which drew largely on probability theory and stochastic processes and led to techniques for determining a source's rate of information production, a channel's capacity to handle information, and the average amount of information in a given type of message.

In layman's terms, information theory is concerned with the reduction of system entropy as well as the preservation of data: "did the complete message get from the sender to the recipient with no loss?" This concern is not limited by nor linked to the importance of the message, just that the message arrives at the right location without degredation. Thus: "Hello fellow PuGers, I will be your tank today." is assigned the same value as "Don't stand in the fire you slackjawed daffodils!" Clearly the first statement is a banality, while the second statement is an important observation which carries life or death consequences. However, in terms of information theory it is that the message is transmitted in its entirety, not the content of the message, that is important.

Furthermore, to preserve signal (message) transmition, the application of channel coding, lossless data compression, and source coding can be applied- ensuring greater information (byte) integrity and contributing to the entropy reduction of the system.

So then, how does this concern someone that is looking to help someone improve their performance, such as the Spell Power DK (SPDK) from Monday's post? Svenn will come back around to this later tying it in with Communication Theory, but in and of itself it is analgous to choosing to /whisper to inform your SPDK buddy that he is misguided in his gem choice vice choosing /2 to transfer the same message. The whisper is a direct channel between sender and reciever and subject to far less "signal" loss than transmitting the same message traffic in the trade channel (Obviously this is a very cursory look at the immediate application- and not a hugely useful one at that, but it will suffice for the time being).

Communication Theory on the other hand takes a different take at much the same set of issues, see below.

Communication Theory: the discipline that studies the principles of transmiting information and the methods by which it is delivered (as print or radio or television etc.); Communication is the production and exchange of information and meaning by use of signs and symbols. It involves encoding and sending messages, receiving and decoding them, and synthesizing information and meaning. Communication permeates all levels of human experience and it is central to understanding human behavior....

While Information Theory ignores, or rather ascribes no value to intentionality, tone, or urgency to a message (as long as the information (bytes) are transmitted with little to no loss and system entropy is reduced), Communication Theory holds the opposite view; as long as the 'meaning' or 'intent' of the message is transmitted the preservation of the bytes is unimportant.

Coming back to our poor SPDK; applying Communication Theory, Svenn can launch into a 20 minute disertation on the virtues of gemming for strength over SP, half of which can be lost in the general tomfoolery of trade chat and still be sucsessful if at the end of it SPDK understands that SP is better left to the Priests and that strength is good for him. Even though SPDK got only got a partial message (unsucessful from an Information Theory standpoint), he is better off than he was, netting at least a partial reduction in entropy.

Furthermore, in Communication Theory, the 'tone' in which the message is delivered will determine in part whether it is successfully transmitted. While no actual signal/ byte loss (as defined by information theory) may occur, there may still exist signal loss. This is due in part because the receiver decoding and synthesizing the information and meaning can arrive at a different message on his own than what was intended by the sender. He may receive all the 'bytes' but extrapolate from them and arrive at a conclusion which may exclude the information contained in the bytes. Example:

Sanctimonius Svenn: message sent "SP is for Priests, are you a priest? No! You want Strength...Noobsauce."

SPDK: message received "original text" received message decoded and synthezied "Svenn is a Jerkface, he has no life>:["

Contrast the above with:
Supernice Svenn: message sent "Sir, I believe you may want to try gemming for strength. While SP appears an attractive option as many of your abilities read like spells and do frost and shadow damage- this is misleading. They are modified by your Attack Power and you may find Strength to give you a better bang for your buck:) ::/puppies, hearts, rainbows, butterflies, etc.::"

SPDK: message received "original text" received message decoded and synthesized "SP bad, strength good ::instant /man crush on Svenn::"

Reliance solely on Information Theory ensures that all the bytes of information are transmitted without signal degradation, but fails to address the informational synthesis that occurs upon reception. So, the original commenter's positing that "A person either wants to learn or doesn't want to learn.There is no such thing as 'wants to learn but doesn't want to learn if bad words are used'. That's not an excuse, that's idiocy." holds true for Information Theory but not for Communication Theory. In the same way, reliance solely on Communication Theory may ensure the salient points of your argument are received and synthesized properly, but will result in an imperfect byte transfer and incomplete knowledge of the subject.

By establishing a threshold of acceptability, say 75% of all bytes transferred and synthesised properly, you can be sure of satisfying in no small part the requirements of both theories, each of which bears relevance on the topic at hand. Mainly, that your SPDK friend will no longer gem Spell Power and has a fairly good idea why.


3 Responses to “Information Theory, Part 2”
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Inno said...

With ::/puppies, hearts, rainbows, butterflies, etc.::" you may earn more than a minor mancrush...

February 10, 2010 at 8:03 PM
Zusterke said...

Wouldn't focusing on both Information theory and Communication theory be the best solution then?
I can imagine it is more important to focus on Communication Theory at first and yet I believe for humans to get the message we could call upon a simple but very effective mechanic from Information Theory: the cyclic redundancy check.
This would enable the receiver of information easily check for himself if he 'understood' the message. Your second reply came close, but it doesn't entirely serve as CRC.

Imagine addressing the SPDK as follows:
"Strength will give you more dps than sp."
Then in a second whisper you can say:
"I believe you may want to try gemming for strength. While SP appears an attractive option as many of your abilities read like spells and do frost and shadow damage- this is misleading. They are modified by your Attack Power and you may find Strength to give you a better bang for your buck:) ::/puppies, hearts, rainbows, butterflies, etc.::"

The reader can track back to the first original line and see if he understood the content of the second whisper. Furthermore, I'm positive that 'because he understood that the second whisper checks out with the information of the first whisper', there will be a stronger sense of confirmation that this information may be accurate or correct.

February 12, 2010 at 5:32 AM
Svenn said...

@Zusteke: Ty, for another insightful observation! (Svenn is a long time lurker at PlusHeal) Applying cyclic redundancy check would certainly serve to ensure the components of both theories, byte integrity as well as correct synthesis/interpretation.

February 12, 2010 at 8:49 AM

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