Glossary » Interaction Design

embedded help

text that is integrated into the user interface and provides instructions right next to the part of the interface that it applies to. It is not a separate help system and not even something that needs to be requested by…

error

(human error) the result of any action whose consequences are not what was intended by the person performing the action. Errors are commonly classified as slips (automatic processes interfering with an action) or mistakes (failures in reasoning or selection of…

escape key

a key on the keyboard used to exit a mode. This can apply to moving upwards through a hierarchy of screens or stopping the execution of a program. Also used to break out of a command mode (where typing issues…

event-driven interface

the kind of interface common to most modern operating systems where the user can initiate actions at any time — the system responds to user “events”, such as typing, mouse movements, or mouse clicks. This is in contrast to the…

explicit destruction

a design principle that suggests that anytime information is permanently deleted (or for that matter, any irreversible action is performed), the user should be required to explicitly indicate that the deletion/destruction is actually desired. This is important when deleting files,…

fail-safe

a property of a device or system that inherently prevents certain failure modes or errors. An example is the inability to start your car when it isn’t in ‘park’.

FAQ

frequently asked questions (pronounced “FAK”); a common form of help for users, especially on the internet. A FAQ list shows the most common questions and provides direct, useful answers. Often, it’s a convenient structure just to minimize dealing with users…

feedback

a reaction to a behavior that has the potential to influence the original behavior. In other words, when a user does something, the computer responds so that the user has some understanding of how the computer interpreted the user’s action.…

forcing function

an aspect of a design that prevents a user from taking an action without explicitly performing another action. For example, writing on a PDA won’t have any effect unless you first turn it on, preventing data corruption from accidentally bumping…

garden path

a sequence of actions a user takes that each seem to be leading to the desired outcome but don’t produce the desired result in the end, such as navigating thru a series of apparently-relevant website links without finding the desired…

groupware

any type of software designed for groups and for communication, including email, videoconferencing, workflow, chat, and collaborative editing systems.

This technology may be used to communicate, cooperate, coordinate, solve problems, compete, or negotiate. While traditional technologies such as the telephone…

GUI

graphical user interface, pronounced “GOOEY”. A user interface that presents information graphically, typically with draggable windows, buttons, and icons, as opposed to a textual user interface, where information is presented on a text-based screen and commands are all typed.

It’s…

guided tour

a form of help system that is a presentation walking through the steps of using the software and demonstrating features along the way.

hand-held device

any interactive machine that is small enough to be held and carried in the hand and usually appropriate for carrying in a pocket. Usually refer to PDAs and other small information appliances.

haptic interface

a user interface based on touch, using the movements of the user as input and the sense of touch as output (both tactile and kinesthetic feedback). Examples include force feedback joysticks and Braille screen readers.

help desk

an organization providing user support for computer and software use, possibly including help with installation, usability difficulties, software bugs, system administration, version and compatibility concerns, and so forth. Help desk software assists people at the help desk in retrieving answers…

hierarchical task analysis

HTA or hierarchical task decomposition, HTD; breaking down the steps of a task (process) performed by a user, viewed at different levels of detail. Each step can be decomposed into lower-level sub-steps, thus forming a hierarchy of sub-tasks. The highest…

hover state

the appearance or behavior of a button or other control while the pointer is over it but the item has not been clicked or dragged; most often used to hilite buttons as the pointer moves across them to indicate that…

human-machine interface

HMI or MMI (man-machine interface); the portion of an electro-mechanical system that a person interacts with, used most often to refer to hardware as opposed to software interfaces. The HMI is the collection of knobs, levers, and monitors that a…

hysteresis

resistance to applied force, e.g. viscosity. Applied to keyboard keys and the feel of resistance they give, and appropriate to all interactions where the interface resists change, lags in response, or dampens the magnitude of the input (e.g. an icon…

immersive interfaces

an interface that heavily involves users by bringing them into the world of the interface both conceptually and perceptually, as in virtual reality, e.g. by surrounding their visual senses (as with VR glasses), giving them stereo sound, and providing an…

in-car interfaces

applications designed for use in a car, such as radios, mobile phones, and GPS systems. Some interface design factors include safety, visual display (if any), rapid use, low cognitive overhead, and hands-free use.

incremental search

a search that progressively finds a match for the search string as each character is typed, as opposed to a delimited search.

indication

showing what item would be selected if the user were to click. Analogous to hiliting the current selection, indication highlights as the user mouses over items, helping the user to accurately make selections.

information appliance

a device for accessing or manipulating information, special-purpose in contrast to a general-purpose computer. The idea is a machine with computing power but designed and used like other consumer electronics, such as stereos, TVs, and toasters. It serves a limited…