Don't Miss

واژه نامه مرجع تخصصی SIGCHI.IR

واژه نامه مرجع تخصصی کارگروه موضوعی ویژه تعامل انسان و رایانه ایرن در حال تکمیل می باشد

A

about box

A dialog box that describes the software product as a whole and the company that created it. The about box typically includes such things as author credits, copyright and trademark information, licensing and shareware information, contact information, version numbers, system requirements, and system configuration.

above-the-fold

For webpages, the area that appears in the first screenful when a person loads a page; the part of a web page that can be seen without scrolling. This is important real estate since users are more likely to spend time viewing these parts while they wait for the remainder of the web page to load and because users often do not scroll down. Remember that many users will likely have smaller screens than the ones that are being used to develop the website on.

access key

A key on the keyboard used as a shortcut to issue menu commands (underlined items in Windows menus).

access privileges

Based on a person’s identity or the identity of their group, access privileges define what capabilities or features are available to them when they access a system, what files they can read or write, what programs they can run, what other users they can interact with, and so on.

Access privileges provide a level of security, preventing users from tampering with aspects of the in which system they don’t belong. Access privileges also allow a system to provide customized interfaces to users based on their roles in group interactions.

accessibility aids

Assistive technology; tools to help people with disabilities to use computers more effectively. Some general categories of disabilities, and some common aids include:

– motor impairments – Sticky Keys and Slow Keys, hardware devices such as head-mounted input devices and eye-tracking systems
– visual impairments – screen enlargement utilities, tactile and auditory output and text-to-speech systems.
– hearing impairments – visible alerts, speech-to-text systems, captioning
– cognitive impairments – reminder systems.

accountability

The principle that in many multi-user situations, someone must be identifiable in order to take responsibility for actions or for decisions. In these cases, anonymity is not always effective or achievable (though users may be anonymous to other users while identifiable to the system).

Someone usually needs to be accountable when safety or security issues are prominent, or when financial commitments must be made. Usually, users must be identifiable enough in order to be held accountable in any situation where someone’s rights may be violated. Accountability needs to be handled carefully to ensure that users can still maintain an appropriate level of privacy in their use of a system.

accumulating attribute group

A set of items or properties that are related and whose effect is cumulative, as with a group of checkboxes. Multiple items can be simultaneously selected, as in a font style menu, where a given letter can be made both Bold and Italic. This is in contrast to an mutually exclusive attribute group (such as a group of radio buttons), where only one item can be chosen at a time.

acronym expansion

When a user enters a relevant acronym (or other abbreviation), acronym expansion automatically spells out the entire phrase represented. While this feature can help in any text entry with commonly repeated phrases, it is especially useful to those who have difficulty typing.

active badge

A small badge that someone can pin to their clothes which enables a computer system to determine their current location. This can be used in groupware systems to provide basic awareness information about coworkers or friends wearing active badges, though obviously, privacy is a major concern.

active value

A programming language extension that allows functions to be called every time a variable (the active value) is changed. Along with callbacks and constraint systems, active values belong to a family of techniques that are extremely helpful in programming user interfaces to maintain consistency between data and their graphical representation.

Unlike callbacks, active values are a mechanism integrated into the programming language, so that programming using active values has simpler syntax and does not require explicit maintenance of the list of functions triggered. Unlike constraint systems, the triggering of an active value will always call the associated functions and won’t resolve cycles. For instance, if a function associated with variable A changes the value of variable B, and a function associated with B changes the value of A, then the active value system will cycle forever (unless the program includes explicit checks for cycles).

adapted computer access

The use of accessibility aids for the disabled with the specific goal of enabling them to effectively use computers.

adaptive interfaces

User interfaces that change over time, in response to how they are used, to improve the quality of the interaction. Examples with current technology include speech and handwriting recognition systems that improve the accuracy of their recognition as they become familiar with the user’s style.

Adaptive systems also include those that detect common user tasks and make these tasks more accessible — making lists of recently-opened files is a very simple example of this. Any adaptive interface has, at some level of detail, a model of the user’s behavior that is refined, and provides an interaction that fits the behavior as best as it can.

adaptive menu

A menu where the most recently-selected item(s) are shown at the top so as to help the user repeat common commands quickly without searching for them in long menus. This technique does not work well with short menus, where it just adds complexity. A common use is for a long font menu, where the user’s last few font selections are located at the top. It doesn’t work well when the number of fonts the user alternates between is larger than the number of recent items that can be displayed.

adaptive palette

A tool palette or toolbar that allows tools to be selected from a pop-up menu, and then shows the chosen tool as the default tool for that menu (can be selected again just by clicking, without the menu appearing). This enables the user to access the most common tools quickly, under the assumption that the most recently-selected tool is the most likely tool to be needed. However, this doesn’t work well when a person needs to alternate between tools within a single pop-up menu.

adornment

An addition to a standard window, such as a ruler or toolbar, that moves with the window or is otherwise associated with it.

aesthetic integrity

A principle that advocates that a design should be visually appealing and should follow common principles of visual design: consistency, a clear identity, a clear visual hierarchy, good alignment, contrast, and proportions, etc.

What constitutes an aesthetically successful design may vary with the application and the audience. A bright and active design may work well for attracting people to store-front displays, but a softer, more soothing design will be far more successful for applications that people need to use all day long. As with all design principles, aesthetics needs to be carefully balanced with other requirements, such as providing adequate information when it is most useful and avoiding confusing the user. Note that aesthetic integrity is not merely “attractiveness”. It implies a visual design that is coherent and well-structured.

affective interface

A user interface that appeals to the emotional state of users and allows users to express themselves emotionally.

affinity diagram

a simple technique for organizing concepts: designers write down ideas on a set of cards and then organize the cards by grouping them and by placing closely related concepts close to each other (e.g. by shuffling the cards on a table or pinning them to a wall); especially useful for uncovering the structure and relationships in a poorly understood domain. Affinity diagrams are often a good next step after a brainstorming sessions. Related “card sorting” techniques are useful for uncovering similar groupings from users.

affordance

A situation where an object’s sensory characteristics intuitively imply its functionality and use. A button, by being slightly raised above an otherwise flat surface, suggests the idea of pushing it. A lever, by being an appropriate size for grasping, suggests pulling it. A blinking red light and buzzer suggests a problem and demands attention. A chair, by its size, its curvature, its balance, and its position, suggests sitting on it.

An affordance is a desirable property of a user interface – software which naturally leads people to take the correct steps to accomplish their goals. The common psychological term for this is stimulus-response compatibility.

AIDA

Attention, Interest, Desire, Action. This classic advertising model says that an advertisement (and by extension, many effective user interfaces) ought to function by getting people’s attention, stimulating their interest, generating a desire, and then finishing with a call to action.

alert box

A dialog box, generally modal, that appears to alert the user to important information.

3 categories of alert boxes are common:

– “errors” are typically actions which can’t be continued
– “warnings” suggest that a problem might occur
– “notes” provide information to a user, but don’t suggest that anything critical is occurring

algorithm animation

Algorithms are the formal procedures for performing some computational task, such as the procedure to sort a set of numbers. An algorithm animation is a graphical display of process over time (auditory cues are also quite common). Algorithm animations are especially useful for teaching and explaining complex processes and for helping programmers to debug their programs. This illustration shows one frame of an animation of the Quicksort algorithm.

alpha testing

A stage of software development where the software is first tested for bugs by real users. In contrast to beta testing, alpha software is usually assumed to have some significant bugs or unimplemented portions.

ALV architecture

Abstraction-link-view architecture. A technique for building software by developing the application as a user interface (the View), the abstract data and semantics (the Abstraction), and a set of relationships between these parts (the Links). This technique makes it easy to add many different types of views onto one abstraction, useful in particular for the construction of multi-user interfaces, but also useful for building debugging systems and for software engineering in general enabling user interfaces and underlying applications to be developed relatively independently. The ALV architecture is similar in spirit to model-view-controller (MVC). ALV differs from MVC in 2 primary ways:

1. ALV is based on a constraint system to manage consistency between the abstraction and view. The links are a special kind of constraint that can create and destroy objects as well as maintain relationships between their values.
2. ALV combines input and output in the view, whereas MVC separates input and output in the view and controller.

ambient media

Devices that monitor information states and display the information continuously in the periphery (that is, without the user needing to consciously attend to the display). This allows the user to be aware of the peripheral information without making an explicit effort and without interfering w/ the user’s primary task.

analytic memo

A brief note used during the coding and construction of data that summarizes a possible interpretation or analysis of the data. Memos help to remember particular analyses and focus future data collection and coding to explore ideas in the memos.

Analytic memos are used most often in qualitative observational approaches, such as ethnography or contextual inquiry, but they can be useful in the process of essentially any type of research. Some other types of memos may also be considered, though the boundaries between them blend: a “theoretical memo” considers possible theories that the data may support; an “integrative memo” seeks to identify relations between different pieces of data.

analytic modeling

The application of user models and interface models to make quantitative predictions of user performance with an interface.

anchor point

(graphics) the point on an object that remains stationary while an object is resized or rotated, for instance, while resizing a window or rotating an image within a drawing program.

Similarly, the point at which a selection begins. For instance, when selecting text, the anchor point is the point at which the user first clicks when dragging to select a range of characters.

antialiasing

Drawing graphics with smooth blends of colors along edges to avoid sudden shifts of color between pixels and give a smoother appearance. When a line is drawn on a computer screen, the common way to draw it in the early days was with black and white pixels on a grid — the line thus had jagged edges. Antialiasing is a method for drawing the line using intermediate gray pixels to smooth it out. Antialiasing can be used for any graphic shape and is used to render letters also (sometimes called “font smoothing”).

Unsmoothed, or aliased, images have sharp corners called “jaggies”. Removing those corners with intermediate colors is called “smoothing”, “dejagging”, or “antialiasing”.

anticipation

In animation, preparation before an action so that the user has some foreshadowing of the action and can more effectively interpret the action. For instance, when a character runs away, the character will back off slightly in the opposite direction before launching off.

anonymity

The ability to participate in interactions with other people without being identified. Anonymity can be at various levels, including hiding a person’s name and other characteristics, such as age and gender; from simply making their name accessible but nonobvious, to helping to make sure that the person is entirely untraceable, and that no identifying information about them is ever available. Anonymity can be useful for protecting people’s privacy and security. Anonymity can also help people participate in conversations without fear of reprisal (helping to encourage open and honest discussions) and with less concern for being stereotyped based on their identity or characteristics. Anonymity creates potentials for abuse. While on the one hand, it can protect people from targeted harassment, it can also protect people who harass from being identified. It can create security problems, and is inappropriate for certain security situations. It also causes problems in situations where someone needs to take responsibility and be held accountable, as in cases where people’s safety is involved.

Apple Macintosh

The first mass-market computer with a graphical user interface, the Macintosh was introduced in 1984. Its operating system is known as Mac OS. Many of the original concepts behind its user interface were adapted from work done at Xerox on the Alto and Star machines and SmallTalk and first incorporated in Apple’s Lisa a few years before the Mac. The 1984 Macintosh was tremendously innovative in its industrial design, its establishment of user interface standards to apply broadly across applications, and its refinement of user interface widgets into extremely easy-to-use components.

aqua

The visual design style of Mac OS X, which most noticeably uses colored transparent buttons.

articulatory directness

How well the form and behavior of an input device (degrees of freedom, range of motion, discreteness of states) corresponds to the type of input values a user needs to express.

artifact analysis

the study of how people use and conceptualize objects, including how people use computers in their work or play. Artifacts may be examined from any number of perspectives, including where the objects are, how many there are, their functional role, their conversational role, their physical characteristics, or their flexibility of use through different situations.

Artifact analysis may be used to supplement observational data and to gain a more thorough understanding of people’s tasks, and may lead to the design of improved artifacts.

artificial intelligence

“AI”; a field of study which examines how to perform high-level thinking on computers. Artificial intelligence research is typically associated with domains such as speech synthesis and recognition, language translation, image recognition, and strategy and planning. AI research is also associated with certain types of algorithms (such as inference engines), data representations (such as blackboards), and general models of thought (such as connectionist networks).

Usability issues are critical in many AI systems, where a human works with the system to work out and apply results (as in language translation systems and expert systems), and when the AI system serves as the user interface for the user (as with speech systems). AI also is applied in some systems to build a computer model of the user, which is then used to help anticipate the user’s needs and optimize the interface (as in computer-aided instruction systems and adaptive systems).

assistant / wizard

A special type of dialog box that takes a user through a step-by-step procedure. Intended to simplify what might otherwise be a more complex procedure if performed, for instance, through direct manipulation.

assistive technology

AT or enabling technology; technology used by those with disabilities or other special needs to help them fully participate in their work and everyday life.

associative activation error

An error that occurs when a thought or related idea interferes with the current action when it isn’t appropriate (like a Freudian slip).

asynchronous groupware

Software used to help people to work in groups, but not requiring those people to be working together at the same time. (asynchronous = not coordinating at a single point in time).

Examples include:
– electronic mail,
– the routing of forms through an office (“workflow”),

– collaborative hypertext systems (such as the web),
– file-sharing systems that allow different people to edit the same file at different times,

– version-control systems, often used in software engineering to coordinate changes made by multiple programmers to the same program,
– document annotation, such as the markup used for editing and proofreading,
– collaborative writing systems.

attention to detail

A design philosophy that emphasizes that what may appear to be insignificant details can determine whether a design succeeds. A design should be fully unified at every level of granularity.

attitude measure

A quantitative value representing the subjective rating or opinion of users reacting to seeing or using a system, as opposed to performance measures like task completion time or number of errors.

attract-mode opening

When a software application is started, it will often immediately enter a sequence which demos or explains or at least shows a lot of pizzazz of the product, especially in games and multimedia titles. This demo mode or “attract-mode” is designed to draw attention, especially in store displays, and to establish a motivation or interest for the user.

auditory feedback

Sounds in response to user activity, such as a click after a keypress, a whoosh accompanying opening and closing windows, or a klunk when a file is deleted. Useful as redundant reinforcement of activities and for those who are visually impaired.

auditory I/O

Sounds used for input and output, which may include speech, musical sounds, naturalistic sounds, and artificial waveforms. Sound as output has the advantage of being accessible to the visually impaired, of being heard even the user needs to be looking somewhere else, and of being understood readily for certain types of sounds (e.g. well-designed speech). Sound as input is useful for people with motor impairments and those who need to use their hands for other tasks (e.g. driving a car), and speech can be a useful input mechanism to enter a menu selection or even free text.

Sound is intrusive, so it can be heard even when it’s not attended to, which can be an advantage and a disadvantage. Sound can be disruptive in many work environments and may not be an effective communication means in a noisy environment.

auditory menus

a list of choices presented verbally, as in a telephone answering system, e.g.: “Press 1 to order brochures. Press 2 to report a maintenance problem. Press 3 for more options.”

augmentative and alternative communication

AAC; technologies that enable those with limited speech to communicate.

augmented reality

Systems that annotate physical objects and environments by displaying into the environment rather than on an independent display device. Typical display mechanisms include projectors that project displays onto physical desktops or head-mounted displays that are semitranslucent, allowing overlays to be seen on top of the real physical scene.

auto-completion

(or auto-fill) a feature of text-entry fields that automatically completes typed entries with the best guess of what the user may intend to enter, such as pathnames, urls, or long words, thus reducing the amount of typing necessary to enter long strings of text.

auto-exit

Or auto-skip; in form fields with a fixed character size, the movement to the next field automatically on completion of the field, used to reduce keystrokes (by avoiding the necessity of tabbing to the next field).

automatic evaluation

A method of measuring the usability of a system automatically; that is, the usability is tested by a software application rather than manually, by a person. Some types of automatic evaluation do not involve users at all. For instance, some types of standards inspections can be performed automatically, as in an HTML-checking tool that tests for cross-platform compatibility or a dialog-layout tool that verifies spacing and alignment properties. A computer can also simulate human interaction sequences (mouse clicks, text entry) to test a product’s robustness. By supplying the computer with a user model, such as a set of goals, tasks, and ways to perform those tasks, a system can be profiled for completeness and to detect likely sources of user confusion. Other forms of automatic evaluation include using logging tools to capture user interaction data and using online feedback forms to capture user impressions and automatically provide summaries of those responses.

automatic scrolling

Scrolling that occurs when a user drags outside the visible region, such as when a user is selecting text across multiple pages. Automatic scrolling is any scrolling that occurs without a user having to explicitly scroll using a scrollbar.

automaticity

A level of skilled performance characterized by high speed, minimal errors, inability to verbally describe the thought process, and low interference with other simultaneous activities.

automation

Using a computer to perform a task previously done by a human; the principle that if the user would always do the same well-defined task in a given context, then the computer ought to just go ahead and do it.

autosave

A software feature that saves the file periodically while the user works on a document. Usually a user would need to explicitly save a file and risk forgetting to. The user would lose data if the application fails (e.g. during a power outage) and the user hasn’t saved. Autosave has the risk on the other hand, of overwriting previous versions of a file and preventing a user from reverting without saving changes. For this reason, the autosave feature often allows backups to be made automatically, may query the user before each save, and can allow a schedule to be determined for when it saves. Another model for saving data is common in database systems — persistence. Persistent systems never require the user to save the data explicitly, but save the data whenever a sufficient chunk of data is modified.

vatar

An online representation or manifestation of a person, generally in visual form. An alternate personality on the internet. An embodiment of a person’s interactions with others in a virtual world.

awareness

The sense of what other people are doing, even when you’re not communicating with them directly. Awareness is useful for coordinating with others in collaborative tasks where direct communication is not always necessary. Awareness also refers to indirect forms of communication even while involved in a direct conversation, such as making inferences about what someone is doing based on the position of their chair or the lighting of their room. Awareness mechanisms in groupware include systems that let you track whether people are in their offices and what tasks they’re working on (e.g. “what file is my co-author working on right now?”).

AWT

Abstract Windows Toolkit; a Java library for development of user interfaces, including standard widgets and layout tools.

B

backward compatibility

Designing software to work with previous versions of itself, e.g. by making files in the same format and working with the same equipment. In user interface design, this also means minimizing the learning curve so that existing users can easily adapt to changes in the interface.

Baker’s equation

BBEE; Baker’s basic ergonomic equation; an expression describing the factors driving the success of a particular assistive technology:

Likelihood of success (S) = M/(P+C+L+T)

where
M = a user’s motivation to complete a task
P = the physical effort required
C = the cognitive effort
L = the linguistic effort
T = the amount of time needed to activate and control the device

balloon help

A help facility in Mac OS that displays a speech balloon over widgets and screen regions when the users pause over them. The speech balloon typically contains a title and a short description.

Similar in some ways to tooltips, except that tooltips typically don’t include descriptions and balloon help can be turned on and off.

bandwidth

the amount of data that can be transmitted across a network during a given period of time. Variance in bandwidth is also an important measure.

banner ad

(web) an area set off from the rest of a web page by its position and appearance to advertise, inform, promote, or highlight important information. A banner ad is frequently a graphic displayed as a wide horizontal band that can be clicked to go to a “payoff page.”

barrel-tap

Holding down the button on a pen (barrel button) while tapping — used as an input technique in pen-based systems.

baseline

baseline is basically where things “are” in the sense that what we see is what is being done by a “majority” within a competitive space. Now you could argue that, because most are doing something, more audiences experience the same thing. But that depends on the weight of what we find in the analysis. If we discover that most content is found under similar/the same labels, then user expectations are best served by doing the same — but this is NOT best practice. This is simply using convention to reduce guesswork.

For example, on one project we had used ‘Feedback’ to label where visitors should contact the client in a number of ways. When given the scenario, “You would like to complain to that their navigation sucks,” every single user looked for “Contact Us.” The argument went, “doesn’t that stifle creativity?” Yes and no. But that convention can change quickly. Basing designs on baseline is, in my opinion, a short-term measure for meeting an immediate need.

at

a flying mouse; an input device that permits pointing to objects in 3-dimensional space by moving the bat around in the air, similar in spirit to the use of a mouse to point to objects in 2-dimensional space.

beaming

sending information by infrared from one device to another, as with remote control devices or when transferring electronic business cards between handheld computers.

benchmark testing

(summative evaluation) a test designed primarily to measure the level of performance, or benchmark, in terms of usability, either so that it may be compared with another design or checked to see if it meets some goal (criterion testing).

benchmarks

Ways of measuring the degree of usability of a system. Examples of these include time to perform a task, number of errors, time to learn a system, and how a user feels after using a system.

Best practices

the things that we do in recognition and presentation of natural workflows, hierarchies and priorities, cues, integration (physical vs. mental), etc. Labels, on the other hand, come and go — best practices endure, for the most part, longer than labels because they’re more about patterns of behavior rather than convention. While patterns may change, they don’t change as quickly as convention. Vocabulary in the English language is a good example of how quickly conventions change; but “best practices” for how to communicate really haven’t changed a great deal over time. Why? Because we have uncovered patterns (via cognitive psychology, etc.) that people respond to with respect to verbal communication, and we have based our practices accordingly. So, while baseline can get us a certain distance, we transcend baseline by application of best practices in ferreting out user goals and task/domain expectations. Other definitions of best practice include:
– A recorded description of process that is recognized by experts as an effective, efficient and/or appropriate method for accomplishing a task. Because a best practice is selected from among competing processes that can yield similar results, it is in effect documented wisdom.
– A method or technique that is recognized by experts as superior to alternatives in its effectiveness and efficiency. Experiences that contribute to success support but are not in themselves best practices.
– Methods and tools that lead to sustainable improvement in quality, productivity, time to market, and/or, communication.
– Processes, practices, or systems identified in public and private organizations that performed exceptionally well and are widely recognized as improving an organization’s performance and efficiency in specific areas.

beta testing

Testing a nearly-finished version of a piece of software, with the goal of finding bugs missed by the developers. Often beta testing is carried out by people outside of the developers organization.

between-subjects design

A study designed to make a comparison of 2 or more designs and that compares them by having one set of users try one design and another set of users try another design, measuring their performance for each design. This usually requires more users than a within-subjects design, but more easily avoids confounds introduced when a single person uses both designs.

beveled appearance

The bevel is the bright or dark edge used on raised or lowered objects in a user interface to give them a 3-dimensional appearance. This pseudo-3d style is quite popular: by giving buttons a raised appearance, they appear to be pressable. Bright edges are usually on the top-left and dark edges on the bottom-right, consistent with a top-left light source.

binocular display

Also stereoscopic display; a display that is composed of 2 separate displays which are directed separately to the left and right eyes. The viewpoint is slightly different for each, reflecting the slightly different view each eye would have when embedded in a 3D scene, thus allowing for a sense of depth. Binocular displays are used in virtual reality systems and any 3D system for which depth cues are especially important. Because the displays are usually up close to the eyes, they often also extend across a wider visual angle in the eye, allowing for a greater sense of realism, and in the extreme, allowing for the use of peripheral vision.

biometrics

The detection and use of unique identifying physical characteristics in identifying users of a system, typically for security reasons to restrict access without the use of passwords. Examples of biometric devices include: thumbprint readers, retina scanners, body heat scanners, and typing-pattern detectors (using inter-keystroke delays). Biometrics can rarely be forged, but unless the biometric devices are secured to ensure that the person who is gaining access is the same person who is being scanned, it is certainly possible to copy the individual data to pose as another person.

bit depth

The number of bits used to represent the color of an individual pixel on a computer screen. A bit depth of 1 would represent that the pixel could only be on-off — a black-and-white display. 8-bit displays can display 256 colors. 16, 24, and 32-bit displays are also common and display thousands or millions of colors.

bloatware

Software with too many features, interfering with usability. Usually a result of adding features over the course of multiple versions of the software and driven by ever-increasing feature lists used for evaluation in software reviews.

blow-suck tube

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

boolean search

A search that allows the user to enter logical expressions including AND, OR, and NOT. This is a common advanced search feature because of its ability to specify desired results very precisely. However, in natural language, “and” is frequently used as a logical OR, and “or” is often, but not always, used as a logical EXCLUSIVE-OR. Users make this mistake frequently in formulating queries.

BPR

Business Process Reengineering, the analysis of how work is done within a business and how it can be restructured for greater efficiency and profitability, especially by examining the workflow within the organization.

brain-computer interface

Or brain-body interface; an interface directly controlled by brain waves as opposed to physical movement. Current state-of-the-art can only distinguish a few brain states, so such interfaces usually are led by yes-no decisions. These interfaces require training and are currently designed for users with “locked-in syndrome”, who have paralysis so severe that a brain interface is one of their only means of communication.

brainstorming

A creativity and problem-solving technique that involves the spontaneous generation of as wide a spectrum of ideas as possible.

brand identity

The aspect of a design that establishes a unique look and feel distinct from competing products but consistent within the product and its product line. The identity has these advantages:

-it maintains a consistency that helps a user orient and remember the structure of the software.
– it informs the user about the context and the values espoused by the application and its developers.
– it helps a user remember and identify a specific product and vendor.
– it establishes a creative aspect to the design that cannot be imitated by competitors without violating intellectual property rights.
– it establishes an aesthetic approach to which the user responds subjectively.

breadcrumbs

On websites, a form of navigation where the current location within the website is indicated by a list of pages above this page in the hierarchy, up to the main page. For example, if you were browsing the products at a department store, you might see the following hierarchy when you’re on the Sneakers page:

Home > Products > Clothes > Shoes > Sneakers

Each of the categories above the current page is usually a link to the corresponding category page.

The term “breadcrumbs” is a reference to the Hansel and Gretel tale where they leave breadcrumbs as they wander the forest so they can find their way home. The metaphor is imperfect because the breadcrumbs do not represent the actual path the user took, but instead the optimal path from the home page to the current page in the hierarchy.

breakdown analysis

A technique for analyzing user interaction sequences which looks at times when users are focused on figuring out how to use the system (a “breakdown”) versus times when users are performing their intended tasks.

Brooks’ Law

“Adding manpower to a late project makes it later.” – from The Mythical Man-Month

bullet

(graphic design) a small graphic element used to label items in a list. Typically a dot, circle, diamond, or square.

business goals

Part of the context in which user interface design takes place is the need for any design to satisfy not only the user’s goals but also the goals of the business producing the application, goals such as profitability and marketability. If a design does not have an appropriate business case, then it cannot succeed in the market even if it is extremely usable.

business rules

Statements specifying constraints and relationships between components of a user interface. For example:

– The Age field may not be less than zero (a constraint on a numeric field widget).
– When the Credit Card Expiration Date is less than Today’s Date, the Credit Card Expiration Date will be displayed in red, and the Submit Order button will be displayed in its unavailable state (a relationship between different user interface components).

Business rules are meant to be a design specification written in plain language. They often accompany dialog box and simple form specifications.

busy pattern

A special way of displaying an icon, button, or other widget to indicate that it is temporarily unavailable because it is being used. Typically the busy pattern is indicated by showing an icon in a light gray dotted pattern. An icon would be busy, for instance, if the application that it indicates is currently running, or if the file it indicates is currently open.

busy pointer

Also called a wait pointer. An icon used for the pointer indicating that a process is being carried out and the software is not currently accepting input. Commonly represented by a watch, an hourglass, or a spinning beachball.

button

An input device both on the screen and in the physical world, typically used to select among on/off states or to activate a command.

C

CAI

Computer-aided instruction; the use of computers in training and education. Traditional techniques of computer-aided instruction included drill-and-practice programs and approaches inspired by artificial intelligence research which used models of learning to model errors learners were making to customize lessons to the specific needs of the student. Somewhat more recent approaches include simulation environments for exploratory learning and a focus on collaborative learning environments (CSCL).

callback

A programming technique common in user interface toolkits. A function can be registered as a callback for an object in the system, which causes the function to be called whenever some event takes place on the object. For instance, a function that displays a help message can be registered with a button so that it is called whenever the button is pressed. Used in the model-view-controller (MVC) architecture.

candy box

In website design, a small box or sidebar that may appear anywhere within a page that hilites interesting tidbits, quotes, small ads, asides, or chunks of related navigation. Often it is a small graphic used like a banner ad and that looks like a button.

capture error

A type of slip (a kind of error) where a more frequent and more practiced behavior takes place when a similar, but less familiar, action was intended. Examples include telling someone your home phone number when you intended to give your work number or typing your name when you intended to type another word that begins with the same few letters.

card sorting

A technique for uncovering the hierarchical structure in a set of concepts by having users group items written on a set of cards, often used, for instance, to work out the organization of a website.

For a website, users would be given cards with the names of the web pages on the site and asked to group the cards into related categories. After doing so, the users may be asked to break groups again into subgroups for large sites. After gathering the groupings from several users, designers can typically spot clear organizations across many users. Statistical analysis can uncover the best groupings from the data where it’s not clear by inspection, though inconsistent groupings may be a sign of a poorly-defined goal for the website or a poor choice of web page names.

caret

A small triangle used as an insertion-point indicator in text entry.

carpal tunnel syndrome

(CTS) a problem with swelling or inflammation around the median nerve in the wrist, causing pain or numbness. Poor wrist support and posture during extensive typing is considered a contributing factor. Some ways to prevent it include improved posture, wrist supports, and taking regular breaks to stretch and rest.

cascading menu

A hierarchical menu or submenu; a menu with items that open up further submenus.

cascading stylesheets

CSS; a method for specifying the look of a web page independent of the markup of the structure of that page.

The original intent in HTML markup was to specify the structure of a page and allow the individual user to determine how that structure should be displayed. Thus, marking something with the <H1> tag indicated it was a header, but would not specifically indicated how headers are formatted, i.e. at a certain font size, spacing, and indentation. This approach worked fairly well in the early days of the web while the users were researchers sharing information about their organizations and research with each other. This approach also works fairly well for making web pages accessible to those who have visual impairments because a browser can be created to present the same information in a non-visual mode.

However, the web quickly became a commercial tool, and was soon used for marketing, entertainment, and challenging communication tasks that required significantly more control over the format of the presentation. The initial temptation was to skip the use of “semantic” tags like <H1> that only indicate the meaning of what they tag and instead use “formatting” tags like <B> (bold) and <font> (for choosing a font) to get the exact effect required. Because this would mean losing the semantic information in the document, users have less control, the document becomes less accessible to the disabled, and automatic processing of documents by computer programs becomes more difficult.

As a result, cascading style sheets were created. They allow the HTML programmer to specify that semantic tags like <H1> have a preferred appearance (font, size, color, spacing, etc.). They also allow multiple documents to share appearance specifications, permitting the change of appearances to be much simpler.

CASE

Computer-aided software engineering, a field that examines how computer tools can be used to support programmers. Examples include tools for visualizing software code, tracking bugs, and organizing software projects.

case sensitivity

Whether an application distinguishes between phrases based on whether the letters are upper case or lower case. If the distinction is relevant, then the system is case-sensitive. Otherwise, it is case-insensitive.

In search engines and in search-and-replace systems, case insensitivity is often the default. Thus, if you type “hci,” you will still be able to find the word “HCI.” Sometimes however, you’ll prefer to set the system to be case-sensitive, for instance, when you want the country “US” to be distinguished from the pronoun “us.”

Another common domain in which case sensitivity is relevant is command-line interfaces and programming languages.

case study

An intensive analysis of a specific example. Case studies are useful for providing an in-depth understanding of complex situations and for suggesting models and mechanisms to integrate with theories. Case studies can also be quite powerful in providing demonstrations that are counterexamples to theories.

CAUSE

Computer-aided usability engineering; tools to automate usability, such as screen layout tools, design checkers, event logging, automated usability testing, diagramming tools, task analysis tools, & tools for software localization.

centralized architecture

An architecture for distributed applications, which may involve multiple processes and which depends on one central process to serialize all events. Serialization is necessary to make sure that actions performed by multiple participants in a conversation are in a single consistent order, so that all participants will perceive a consistent view of the order of events.

change bars

Lines along the edge of text that indicate where changes have been made since the previous version of the text. These are useful when multiple people have been editing a document together and need to track each other’s work. Change bars may be coded in various ways (e.g. by color) to indicate who made the changes or what type of change has been made (insertion, deletion, spelling correction, …).

chat

Software that enables multiple people in realtime to write messages in a public space, usually in typewritten text. As each person submits a message, it appears at the bottom of a scrolling screen.

Chat groups are usually formed by having a list of chat rooms to meet in. Rooms may be identified by name, location, number of people, topic of discussion, and so forth. Many systems allow for rooms with controlled access or with moderators to lead the discussions. Almost all of the interesting issues in realtime groupware are manifested in direct ways by chat rooms, including issues of anonymity, following the stream of conversation, scalability with number of users, and abusive users.

While chat-like systems are possible using non-text media, the text version of chat has the rather interesting aspect of having a direct transcript of the conversation, which not only has long-term value, but allows for backward reference during conversation, and which makes it easier for people to drop in a conversation and still pick up on the ongoing thread of discourse.

chauffeured prototype

A prototype, typically done as a paper-and-pencil version of the interface, that the designer walks through with the user and manually demonstrates how the interface would respond to user actions. For example, the user might say “I’d click this button”, and the designer would pull out a dialog box on paper that would appear. The advantage of a chauffeured prototype is that not all pieces need to be assembled but interactivity can still be tested; the designer can spontaneously create any missing pieces based on what the user needs in any given scenario.

checkbox

A small box used in forms or dialog boxes that users can check on or check off. Unlike radio buttons, checkboxes are mutually exclusive – the value of one checkbox is usually entirely independent of the value of any other.

CHI

Computer-human interaction, pronounced “KIE” (hard k, long i). HCI is the most common term for the field, but CHI is the term used (probably because it’s easier to pronounce) for the annual CHI conference sponsored by ACM SIGCHI (special interest group on CHI).

chiseled appearance

The appearance that lines have been etched into a surface, by using adjacent dark and light lines casting the correct shadow (usually assuming a top-left light source). This style should be avoided for text because of its poor legibility. In the Windows interface, the chiseled appearance is used to indicate items that are unavailable. In the Java look and feel, the chiseled appearance is used to achieve the flush-3d style.

chording

An input mechanism which requires pushing more than one button simultaneously in different patterns to represent different letters or commands.

“Chording keyboards” allow rapid entry of letters and words which can allow faster typing than conventional keyboards and permits one-handed operation of keyboards.

“Chording mice” are mice with multiple buttons where clicking with more than one button is equivalent to having an additional mouse button.

Chording is a powerful tool for some users, but chording is more difficult to learn and should never be required of users. In particular, many people with arthritic conditions or other motor impairments may find chording extremely difficult (though note that one-handed operation may be extremely helpful to users without the use of one hand).

chrome

A visual style for user interfaces that presents widgets as beveled 3-dimensional objects, usually with a gray, metallic appearance. In this style, buttons are presented as raised rectangles, text-entry fields and other content areas usually appear in beveled insets, and bumps and parallel ridges are often used to indicate that something is draggable.

Also, the “chrome” of an interface refers to the area of the interface taken up by controls, as opposed to the content area of the interface.

chromostereopsis

A phenomenon of visual perception: different wavelengths of light focus at slightly different depths in the eye. Thus, it is difficult to focus on an image that combines two colors because each color is fuzzy when the other color is in focus. This is especially a problem for images with red and blue.

This problem can be avoided by creating an image without both colors side-by-side, by using black or white boundaries, and by increasing the contrast (difference in brightness) between the two colors.

Claims analysis

analyzing the relationship of design parameters to the usability of an interface. A claim is a statement that a certain aspect of a design, such as the location of a button, the interactive style of a scrollbar, or the feedback given in response to a user command, has certain psychological implications that are reflected in how capable a user is in using that design.

In claims analysis, artifacts of the user interface are listed along with their design features and all relevant positive and negative implications of each design feature are listed. This approach can help to select among alternative designs, and clarifies the questions to be analyzed through user testing by stating how the design should work as a set of well-defined claims.

Clearly marked exits

– principle that users should be able to easily cancel or undo an undesirable operation; essentially the principle of reversibility or forgiveness. Examples include:

– Cancel button in dialog boxes

– an Undo command
– the ability to terminate an ongoing operation with a Cancel/Stop button or a keyboard combination such as Control-C or Command-period
– clear navigation on a web page to return to a previous page or a home page