Glossary » Multimedia

squash and stretch

in animation, elastic distortions of shapes during motion, especially of living creatures, to reflect the stretch of elastic body tissue, such as cheeks stretching and bulging during chewing. These distortions may be exaggerated to clarify an action, but the common…

staging

in animation, the choice of composition, viewpoint, and acting to communicate most effectively without confusion, distracting details, or tradeoffs that sacrifice clarity.

stereopsis

the perception of depth based on the differences in images that reach the 2 eyes.

storyboard

a series of illustrations that represent a process, such as the steps of interacting with a computer or frames from an animation or movie. Storyboards are useful for presentations, such as with focus groups, and for checking that the steps…

symbol segmentation

automatically identifying the boundaries of individual meaningful units within a continuous input stream, such as a computer identifying individual words within spoken speech or identifying individual letters in handwriting. In simple circumstances, such as slowly and distinctly pronounced speech or…

tactile interface

a user interface that uses touch for input and/or output, such as a Braille reader.

tele-embodiment

especially in virtual reality systems, taking on a specific form when communicating with someone. The form may be a representation of your own physical body, someone else, a fantasy creature, or an abstract entity.

tethered viewpoint

a virtual reality or immersive environment where people’s actions control a remote representation of themselves, an avatar, or a device, that they can watch and control within the environment, as opposed to thinking of themselves as directly inside the environment.…

text-to-speech system

software that takes written text and speaks it using some kind of speech synthesizer. Text-to-speech systems are useful for the visually impaired, and for situations where users are not able to view the computer screen at all times, such as…

time compression

in auditory interfaces, speeding up playback to improve the speed of listening. Up to a limit, this compression can be done without significant distortion of the audio. This is useful in playing back voice messages or to speed up audio…

time-stamping

in various approaches to recording and logging user behavior, time stamps record the time at which the recorded events occurred. Time stamps can appear on videotape recordings, website hit logs, and logs of key presses and mouse clicks.

transition effects

visual effects that animate the transition from one visual display to another, used especially in presentations and video. Effects include fade in and out, pan (left, right, up, and down), zoom in and out, checkerboard patterns, and wipes. Transition effects…

video coding

or video transcription; the systematic recording of the contents of recorded video. While coding may note any number of characteristics in the video, typical coding involves a text transcript of words spoken and who is speaking, indicating such things as…

video communications

systems that allow two-way or multi-way calling with live video, essentially just a telephone system with an additional visual component. Primarily because of cost (but also compatibility problems), early use of video systems was primarily in advance-scheduled videoconference meeting rooms.…

video prototyping

a technique for visualizing the interactive behavior of a system using video animation. Each frame of the video is created by videotaping a brief instance in the use of a system. Each frame is typically constructed on paper with icons,…

videoconferencing

systems permitting people at separate locations to communicate via video and audio.

Some common design considerations for videoconferencing systems include:

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videotaping

a data capture technique sometimes used in many types of user studies, such as usability testing, focus groups, and interviews. Get permission from users before videotaping them. Video can be used for several purposes:

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voice output communication aid

VOCA; a device used by those with speech impairments that uses computer-generated speech to communicate.

voxel

a volume-element; a 3D equivalent to a pixel (picture-element). 3-dimensional scenes can be constructed by setting the properties of individual voxel, such as color or texture.

VR

virtual reality; the modeling of 3-dimensional worlds that can be moved in and explored; a 3D interface whose metaphor is an actual world that people inhabit instead of just looking into it, used, for instance, for games and interpersonal communication.…

VRML

Virtual Reality Markup Language; a simple notation for describing 3-dimensional spaces and links between different sites, allowing 3-D spaces to be browsed like websites and other hypertext.

wireframe

(website design) a skeletal version of a website or product that represents navigational concepts and page content. The term is used in 2 broad ways:

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