February 1996 — Features
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Toward an Understanding of Media Psychology
The psychology of multimedia is not well understood and what is understood is not widely known in the development community. At present, developers have limited sources from which to learn about media psychology.
The new media psychology includes the study of how the mind and emotions respond to a multiplicity of sensory stimuli. Understanding the perceptions, emotions, understandings and behaviors one wishes to achieve is fundamental to the purpose, architecture, design and construction of new software. This comprehension is in addition to, and synergistic with, understanding theories of intelligence, learning, communication and cognition.
Developers Must Make Choices
Technical breakthroughs now allow enormous amounts of data to be placed on a single 4.7-inch compact disc. A standard disc can hold over 600MB of data but this is quickly gobbled up by the rich imagery and sound of today's products. Assembling a product requires a variety of layout techniques and choices to "manage the bit geography" on the surface of a disc.
Although most CD title developers are knowledgeable about what the technical choices are, few understand the cognitive and emotional impacts resulting from their choices.
The size of the disc is not the only constraint. Much of what we experience in a CD-ROM application is bound by the delivery rate from the CD drive, just as the quality of a cable TV or radio program is limited by signal bandwidth. The difference is that on a CD-ROM, the designer decides how much of the available bandwidth will go to various components: sound, images and data.
For sound, the amount of disc space and the bandwidth attributable to audio will affect, respectively, the total length and quality of the sound on a product. At the highest fidelity audio used for music CDs (16-bit, 44 kHz) a designer can barely fit 72 minutes on a disc. By lowering sample rates and using various compression schemes a designer can get over 19 hours of sound on a disc. The impact that the audio-quality choice has on the cognition and experience of the user is what has to be decided for each sound byte.
For images, a designer may choose a color palette with as little as two color choices (1-bit), to as many as 16 million color choices (24-bit) &emdash; the typical application uses a palette of 256 colors (8-bit). Each variation in the number of colors uses greater or smaller amounts of space on the surface of a disc, so decisions about color images are controlled and managed by the amount of "real estate" available on the disc and the delivery rate (bandwidth) needed. Again, what impact the color image decision will have on the cognitive or emotional experience of the user is a question which needs to be answered.
