Glossary » Design Principles

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.

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…

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)

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.…

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-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.

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…

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…

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.

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…

UCD

user-centered design: design around the needs and goals of users and with users involved in the design process, design with usability as a primary focus.

unique selling point

USP; the differentiating factor that distinguishes a software product or website from its competitors. Its niche.

universal access

the ability of everyone, regardless of age, nationality, disability, or any other factor, to access and take advantage of computers.

usability

the characteristic of being easy to use, usually applied to software, but relevant to almost any human artifact. What makes an artifact easy to use? Broadly, something is easy to use to the extent that it effectively performs the task…

usability death spiral

the condition where the longer a programmer or designer spends dealing with a particular piece of code (without observing real users using it), the more logical and usable it appears to be.

This is a metaphor to the aviation “Death…

Usability First

the principle that in designing software and other human artifacts, the most important goal is to design for usability. That is, design products for people that help them do their work in an effective and satisfying way.

Usability First™ is…

usability metrics

or benchmarks; formal measurements that are used as guides to the level of usability of a product. Metrics include how fast a user can perform a task, number of errors made on a task, learning time, and subjective ratings.

usable

able to be used, easy to use. Software that interacts with people in an efficient and effective way, minimizing confusion and mistakes. Easy to learn, safe, error-free, delightful, useful.

usefulness

the extent to which software actually helps to solve users real, practical problems. A system may be easy to use but not relevant to the actual needs of a user. Usefulness depends to a large degree on the features and…

user interface guidelines

lists of principles for user interface design, ranging from broad statements such as “be consistent” to extremely specific details such as “use an ellipsis (…) at the end of a menu item to indicate that the command brings up a…

user-friendly

a popular term used to describe something that is easy to use (usable). The term is used quite loosely, but usually refers to systems that are pleasant to use and easy for beginners to learn.

walk-up-and-use

describes systems intended to be used by first-time and one-time users who need to be able to effectively use the system without any training; for example, public information kiosks, museum displays, and ticket-purchasing systems.

warning

a message to a user that lets a user know of potential dangers, such as the possibility of data loss if they continue an operation; a type of alert box that provides such a message. A typical example is the…

wow factor

the degree to which the first impression of something makes a person say Wow! A surprise, originality, coolness factor.