Effective Multimedia

There are two key factors involved in determining that blend; network bandwidth, and cognitive bandwidth. While network bandwidth, is a rather obvious factor, as anyone who has downloaded QuickTime videos over a 14.4 modem can attest, cognitive bandwidth is a far more crucial issue. By cognitive bandwidth, I am referring to the time and mental effort it takes for the senses to take in and the mind to process.

Due to the ever-increasing amount of information we need to take in to function in contemporary postindustrial society, the demand on our cognitive bandwidth has significantly grown. Properly blended multimedia reduces our cognitive bandwidth load by semantic compression. Semantic compression refers to the density of information transmitted by given media. The cliche, "a picture is worth a thousand words", describes the high semantic compression of graphic images over text.

From low to high compression, media are ranked as follows: text, audio, still images, and video. The base semantic compression is increased if the message or effect triggers cultural archetypes or memories of individual human experience. Triggering these increases the overall information density by blending it in with previously stored information. For example, a simple phrase, such as 'first love' can trigger a very dense multisensory information stream, complete with reenvoked emotions.

Semantic compression is also heightened by increasing the level of user interactivity with the information stream. This heightening is the result of the mind focusing its resources on the information.

Thus the well thought out use of an interactive blend of high semantic compression media, with the message or effect designed to evoke cultural archetypes or individual memories, makes optimal use of the user's cognitive bandwidth. When the choice is between optimizing cognitive bandwidth or network bandwidth, chose cognitive bandwidth.