Glossary » t

tab traversal order

the order in which widgets on the screen accept user input as the user tabs between them. In entering forms, this typically means the order in which text fields are entered, but may also apply to checkboxes and other buttons…

tabletop display

a display built into a tabletop. This may be advantageous in helping people to view it from many positions, including sitting and standing, in an environment where they need to be moving around frequently, in enabling multiple people to view…

tabs

an interface metaphor for navigating between screens or between different panes within a window, based on the idea of tabs on folders in a file drawer.

tactile interface

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

tangible user interface

a user interface whose input and/or output are tangible objects that typically directly represent information in the application domain (as opposed to a mouse, which provides abstract, domain-independent input). Examples include interactive plush toys, blocks, and toy cars.

tapping

an input technique, used especially with pen-based systems. A tap is a rapid touch then withdrawal from the surface. A screen is tapped with a pen or a touchpad is touched by a finger to indicate selection of an item…

target audience

the set of users that a system is intended for. Constraining the target audience can be useful to simplify the design problem, but obviously limits sales of an application. Typical parameters of the target audience include: industry, computer experience, income,…

target configuration

or “target platform”; the technical parameters of the system(s) that a piece of software is being developed for, which impacts how many users will be able to use the software as well as the difficulty with which a user can…

task analysis

a set of methods for decomposing people’s tasks in order to understand the procedures better and to help provide computer support for those tasks. The basic approach is to define the task and the goal of the task and then…

task completion time

a measure of the time it takes a user to perform a task (from start to finish). This is a typical metric in usability evaluation.

task-based help

or “task-oriented help system”; instructions for users that are given in terms of step-by-step procedures for performing tasks. This is in contrast to help systems that simply provide explanations of what different parts of the program are and what they…

taskbar

an on-screen bar showing the currently running applications and open documents, as well as indicating system status, best known from the Windows 95 operating system. The taskbar provides rapid navigation between documents with relatively minimal screen clutter.

tear-off menu

a menu that can be made into a window (a floating palette) by clicking on it and dragging outside its normal extent until a small outline follows the pointer to position the new window. This is especially useful if a…

tech tree

in strategy games, the set of technologies that can be developed, organized in a rough hierarchy where each technology can be developed only after its parent technologies have been developed.

technical writing

creating text that communicates facts in a simple, direct, and effective manner. Technical writers do not only write ABOUT “technology”. They also write FOR technological systems, such as computer software. They may write instructions, labels, dialogs, warnings, help systems, manuals,…

technological determinism

the concept that technology is the primary component of business success. Thus, buy more technology. Obviously, it’s not always true, and the fit of the technology to the organization can weigh enormously on the issue.

technology push

technology development that is driven by ideas or capabilities created by the development organization in the absence of any specific need that customers may have. In technology push situations, innovations are created and then appropriate applications or user populations are…

technophobia

the fear of technology; the reluctance to use or learn how to use computers. Most often, this term is used inappropriately to blame users for their distaste for technology when in fact the technology truly is to blame for its…

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.

telepointer

a graphic (usually an arrow) used to indicate where another user is pointing, as in a shared whiteboard. The motions of a telepointer can be used as gestures to communicate with other users.

teleworking

working at a distance from your office or workplace, using telecommunications technologies to access the information at your workplace, i.e. telecommuting.

ten minute rule

“Any system which cannot be well taught to a layman in ten minutes, by a tutor in the presence of a responding setup, is too complicated.” — Ted Nelson (Dream Machines, 1974)

term rotation

in an index (such as for finding information on a website), listing multi-word terms under each significant word in the term. Thus, “information architecture” would also be listed under “architecture, information” and “graphical user interface” would also appear under “user…

test protocol

the set of steps to perform a user test, typically written out as a script and included with test materials as a specification for the entire testing process.

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 entry box

a box into which text can be typed, as opposed to areas in which text is simply displayed but can’t be edited.

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…

the digital divide

the split between those who can access and use computing and technology and those who can’t. A variety of factors may serve to exclude people, including poverty, low literacy, low computer literacy, disabilities, low education, rural geography, and under-developed countries.…

theme

a set of user preferences that collectively determine a cohesive custom appearance to an interface. A theme may specify properties such as a color scheme, set of fonts, style of imagery, sounds, and interactive behavior.

thesaurus

a collection of synonyms defined to help handle the wide variety of terminology people may use in indicating the same objects or commands, especially useful in search engines.

think aloud protocol

a technique in user testing where users are asked to speak their thoughts as they perform a task.

While the focus in user testing is primarily on how effectively a user performs the required tasks (and not on how users…

threads

in group communication, a conversational thread is a line of discussion with a common theme where each contribution follows from the last. A group may have multiple simultaneous threads continuing at any given time, and threads may be woven into…

thumbnail sketch

(graphic design) a small, rapidly-drawn sketch, used to explore visual ideas, focusing on rough layout issues. A general design approach is to quickly draw a large number of thumbnails as a way of brainstorming and exploring design variations.

thumbwheel

a spinning wheel usually spun by a thumb and generally located on a keyboard or mouse or on handheld devices (such as handheld radios). It can be used, for instance, to set values or to quickly scroll or move a…

Thurstone scale

a way of measuring people’s attitudes along a single dimension by asking them to indicate that they agree or disagree with each of a large set of statements (e.g. 100) that are about that attitude. The statements are designed to…

tiering

a way of taking the tasks to be performed and putting them in several tiers . The most important are readily available; the less important tasks are on subsidiary levels. Designers used to put all tasks on the menu bar…

time

a typical measurement in usability studies, and a typical metric for target system performance, including for instance: response time, learning time, and task completion time.

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.

timeline

a method for prototyping and visualizing processes; a type of storyboard. In contrast to an ordinary storyboard, a timeline can be especially useful for displaying simultaneous processes, such as two people working simultaneously who need to coordinate their work at…

timesharing system

a computer designed to support multiple simultaneous users, usually with the intent to minimize their impression that any other user is on the system and not intended to allow the users to communicate. Unix systems are common timesharing systems today.…

toggle button

a button that changes between 2 (or sometimes more) states when pressed, such as a checkbox or a disclosure triangle.

toggle key

a key on the keyboard that toggles between two modes. The most common is the CAPS LOCK key which causes all letters to appear as capitals when it is activated. Other common toggle keys include NUM LOCK (alternates between the…

token-passing floor control

(also baton-passing or chalk-passing) a means of floor control that allocates the floor to the person who holds the token. The token can be passed to another user, possibly by simply releasing it and having it go to the next…

tongue-activated joystick

an input device for users with limited mobility; a tongue-activated joystick is placed in the mouth and manipulated with the tongue. It can be used in conjunction with a blow-suck tube to move a pointer around and make selections.

tool

traditionally, an icon that could be selected that would set a mode for user input, such as a paintbrush in a drawing program. Nowadays, a tool may refer to any icon that can be pressed and takes effect immediately, even…

toolbar

a small window, usually a floating palette, with a set of small icons that perform operations or set a mode of input, such as the drawing tools in a drawing program (paintbrush, pencil, eraser, fill tool, lasso, etc.).

toolglass

a semi-transparent window that contains tools to choose from, usually brought into view temporarily to access tools without significantly obscuring content information below the toolglass.

tooltip

a small label that appears beside a button or tool if a user pauses over it, generally only a word or two. Similar in concept to balloon help, except that balloon help allows for a more extensive description and can…

touch interactive display

TID; an input device that overlays a screen, or touchscreen, that recognizes where the user touches as input.

touch tablet

or drawing tablet; a large flat surface that a user can touch with a hand or a pen (or a puck) to control the position of the pointer on the screen. Touch tablets typically work in absolute coordinates, meaning that…

touch typing

a level of typing skill characterized by the lack of need to visually locate the letters on a keyboard. Touch typing represents skilled performance, but not necessarily expert performance.

touchpad

an input device used for moving the pointer on the screen, much like a mouse. A touchpad is like a small touch tablet that uses relative rather than absolute coordinates. They are common on portables because they allow users to…

touchscreen

a screen that has a touch-sensitive film over it, allowing a user to touch areas of the screen to move the pointer and press buttons, thus allowing a very direct interaction with an image. Touchscreens are most commonly used in…

trackball

an input device consisting of a ball set into a base that can be spun to move the pointer on the screen, essentially equivalent to a mouse, but having the advantage of being in a fixed location and therefore requiring…

tradeoff analysis

making decisions when each choice has both advantages and disadvantages. In a simple tradeoff, it may be enough to list each alternative and the pros and cons. For more complicated decisions, list the decision criteria and weight them. Determine how…

trail

a sequence of documents that form a coherent message within a hypertext or web collection. Each document points to the next and previous documents along the trail.

training

teaching people how to use computer systems. Training time can be a critical factor in the cost effectiveness of a computer system, and thus a critical usability factor in design. Trainers get a lot of exposure to the learning difficulties…

training wheels interface

a user interface that hides or disables advanced features to make it easier for novices to familiarize themselves with basic features. Users can then turn on the more advanced options when they’re ready.

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…

translucency

the property of an interface whose method of use is obvious once general background information or the basic system metaphor is understood.

transparency

the property of an interface whose method of use is readily apparent; obviousness or intuitiveness.

trash can / recycle bin

an icon on the computer desktop that represents a container for deleted files. (Note how the idea of putting your trash can on top of your desktop violates the metaphor of an office desktop.) Files are dragged to the trash…

tree diagram

a visual way of representing hierarchies, commonly used, for instance, for representing organization charts. Also useful for displaying file systems and sitemaps for websites. A tree diagram represents the hierarchy by displaying each object in the hierarchy as a box…

tree view

a control that displays a hierarchy, such as the directory structure of a file system, and allows sections of the hierarchy to be expanded or collapsed to examine the contents, using a disclosure triangle (Mac OS), turner (Java), or “+”…

TreeMap

a diagram for representing hierarchical structures (trees). A TreeMap displays the hierarchy as a series of embedded boxes, where each box contains its children, usually by alternating at each level between laying them out vertically and laying them out horizontally.…

trending

making predictions about the future based on previous trends in order to anticipate the target environment for a design, which may differ from the current environment, e.g. by anticipating industry trends, changes in computer power, competitor actions, market preference changes…

triangulation

the use of multiple methods to provide converging evidence toward reaching a conclusion. For instance, if users report during interviews that they find a label confusing, and during user testing the users show difficulty in understanding the same label, then…

triple-tap text entry

in phone interfaces, using the numeric keypad to enter text by pressing each digit 1 to 3 times corresponding to the 3 letters each key is marked with.

TTY

teletype; an ancient terminal that displayed all input and output by printing it on a line printer.

turn-taking

to speak or act while no one else is and then to pass the floor onto another person through a glance, gesture, or speech pause; that is, a policy for floor control where only one person can speak or act…

turner

a small circle with a line used in tree views to expand and collapse sections of the hierarchy; when it is clicked it turns to the right to indicate a collapsing section or down to indicate an expanding section.

typeahead

a feature for allowing users to continue typing without waiting for the computer to catch up. For instance, a word processor may not display every keystroke as it’s entered because of difficult screen formatting, but will catch up as soon…

typography

the design of letterforms, and the selective use of appropriate type (in appropriate fonts) for the display of text. Typographers often specialize in the design of fonts and of logos, but typography plays a role in any context in which…