Glossary » v

valuator

a general way of referring to any input device or input method for specifying continuous values (as opposed to selecting among a finite set of choices). Typical devices include control dials and levers.

VDU

visual display unit; a screen or monitor. Also, VDT, visual display terminal.

vector display

a technology used for computer monitors that moved the electron beam in a CRT directly along the paths between specified points on the display, creating very sharp, smooth lines and requiring very little memory to refresh the display. Vector displays…

Venn diagram

a common diagram used in set theory. Each set is represented as a circle (or other bounded region) and labeled with a capital letter or word. Any member of the set that is specifically denoted (which is optional) is represented…

verification

the process of determining that the results of a design or development phase are consistent with the design specs that were provided for that phase.

vibratory feedback

feedback a user gets from a physical device that can vibrate, such as a pager indicating an incoming message or a joystick vibrating when a user pushes its value outside a safe operating range.

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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vigilance task

a type of task where a user must maintain attention on the task while waiting for an uncommon, unpredictable event, such as monitoring security cameras or a radar display.

virtual community

a community that exists solely in terms of electronic as opposed to physical interaction, such as a group of people on a shared mailing list or newsgroup.

virtual device

an abstract specification of an input or output device that enables a programmer to interact with that device without knowing the details of the specific device, e.g. by using a printer language to send output to a printer without knowing…

virtual terminal

A virtual terminal defines a set of capabilities that an application working over a network can assume that a user has at the user’s local site. It responds to a network protocol that allows the specification of interactions with the…

virtual toolkit

a cross-platform user-interface toolkit. With a virtual toolkit, the user interface is developed with a layer of abstraction in calling up widgets and dialogs. The virtual toolkit translates requests for windows, buttons, scrollbars, and so forth into the appropriate calls…

virtual value chain analysis

a “virtual value chain” is a business model for the information services industry, developed by John Sviokla. The value chain starts with the Content provider, then goes to the Information Infrastructure for distribution and transactional support, and then to the…

visual brainstorming

the process of generating a variety of graphical alternatives to a visual design problem, such as generating thumbnail sketches for a screen layout or various alternatives of an icon to represent an abstract concept.

visual impairment

low vision, color blindness, or blindness. Low-vision users need the ability to scale fonts and images and need optimal contrast and legibility. Blind users need to access computers through non-visual modalities, such as screen readers or Braille output devices.

visual interaction design

(VID) design of interactive systems with an emphasis on the visual or graphic elements. Strongly influenced by the graphic design perspective, visual interaction design integrates concerns with how users provide feedback to visual systems and how the flow and interaction…

visual programming language

a programming language whose interface is graphical, as opposed to the most common textual languages (such as C, Lisp, Java, etc). The idea is to improve the comprehensibility of the code by choosing an optimal notation, not one which is…

voice output communication aid

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

vortal

vertical portal; a website that organizes a set of links to other sites within a given domain (vertical industry).

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.