Glossary » f

face validity

the apparent appropriateness of an experimental design in resolving the question it is intended to address, at a subjective level.

face-to-face

or FTF; people interacting with each other in the same place, as opposed to over a telephone, for instance. Refers to group meetings, group work, and groupware interactions which are co-located, in contrast to “distance” or “distributed” work.

facilitator

a person who leads meetings to help make the meeting process successful, e.g. by helping to establish meeting goals, encourage input from all participants, help the meeting flow from one topic to the next, and ensure suitable completion of issues.…

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’.

familiarity

the degree to which a user recognizes user interface components and views their interaction as natural; the similarity of the interface to concrete objects the user has interacted with in the past. User interfaces can be familiar by mimicking the…

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…

favorites list

any shortcut designed to help users mark their favorite items and then revisit/reuse those items quickly, such as the use of bookmark lists to mark favorite web pages or lists of favorite files in file dialogs. Favorites lists are similar…

feature inspection

a usability inspection technique that identifies the tasks that a user would perform with an application and the features of the application that would be used to perform those tasks. Each feature is then evaluated for whether it is understandable,…

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.…

feedback form

a type of questionnaire designed to get a reaction to some recent experience of a person, such as a recent experience with a website or a software package.

field

a box for entering text or numbers, usually found in forms and dialog boxes.

field testing

testing a product in the actual context in which it will be used, as opposed to laboratory testing, or testing the product in its development environment. Field testing can be useful for spotting a wide range of interaction problems such…

fingertip controls

keys that are activated by touch, without having to actually press them down. These are common, for instance, on microwave ovens because they are easier to clean. They should not be used in all applications because they are easier to…

fisheye view

a way of representing data visually such that more important information is represented larger than less important information. For instance, a map could be displayed as if through a fisheye lens, distorting the focal point to be extremely large.

Fitts’ Law

T = k log2(D/S + 0.5), k ~ 100 msec.

T = time to move the hand to a target
D = distance between hand and target
S = size of target

Fitts’ Law is a model to…

flat screen display

or flat panel display (FPD); a screen that is very thin, potentially using a variety of different technologies, such as LCDs and gas-plasma displays. In contrast, because of the need to direct an electron beam across the whole display, CRTs…

flicker

in CRT displays, the screen is rapidly refreshed, generally 50-100 times per second. In between refreshes, phosphors dim, but the human eye will only perceive the average luminance provided that the refresh is frequent enough. Unfortunately, the periphery of our…

floating palette

a window that is subsidiary to the main document window. It has a special small title bar and it floats above standard windows even when it is not the current focus. A floating palette is typically used for options and…

floor control

the mechanism by which access to a shared object is mediated — for instance, controlling access to a shared whiteboard (so only one person can draw at a time) or determining who can speak during a chat session (determining who…

flowchart

a visual way of representing a task or procedure, traditionally used by programmers to visualize the flow within their programs. Steps of a process are represented in boxes and flow is represented by arrows connecting the boxes. Input and output…

flush 3d style

a visual style for widgets in pseudo-3d interfaces; the edges of the graphic are rendered in a chiseled appearance so that the objects appear to be at the same depth as the surrounding space (the “chrome” of the interface).

focus group

a group of potential users or stakeholders in a product who are brought together to gather information as input to the design process. When the users are current users of a prior version of a product, the questions for them…

focus ring

a ring surrounding a default button in a dialog box, used to hilite the button and indicate that the button will be activated if the Return or Enter key is hit. In many dialog boxes, the focus can be moved,…

focus+context

a principle of information visualization — display the most important data at the focal point at full size and detail, and display the area around the focal point (the context) to help make sense of how the important information relates…

fog of war

in strategy games, explored regions are typically mapped automatically, but enemy activities are only visible on the map when they are within the line of sight. The fog of war refers to those mapped regions where activities can’t be seen.…

folder / directory

a method of organizing and navigating files on a computer. Files are stored in a folder (or directory) which can also contain subfolders, thus creating a hierarchy of files.

foley button

a button that plays a short sound used for sound effects, e.g. laughter, applause, giggling, coughing, crunching, wind, door-slams, etc.

follow through and overlapping action

in animation, certain parts of an animation must keep moving even after the main action has completed, e.g. when a woman swings her head, her hair continues moving after she stops moving her head, and this hair motion may continue…

foot pedal

or “mole” (an underground “mouse”); an input device that is controlled by a person’s foot, useful for entering boolean values (up or down) or values along a continuous range. Foot pedals are common in cars, pianos, and sewing machines. From…

force feedback

the application of physical force in response to user input. Used, for instance, in arcade games and car and plane simulators. A force feedback input device, such as a mouse or joystick, can provide redundant tactile feedback of what’s on…

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…

forgiveness

a design principle that says people should be able to recover from their inevitable mistakes. Dialog boxes should have a Cancel button. Operations should be undoable. Long operations should allow a user to stop them in the middle.

The most…

form follows function

a design aesthetic that encourages design to be grounded on the functional, useful forms inherent in the application. This avoids gratuitous decoration but elevates the human task and the meaning of the object as the principle aesthetic.

formal usability methods

methods to specify user interfaces, where “formal” means that the specification notation is unambiguous, as in mathematical or computational representations. Formal methods may be used to simplify specifications, to automatically generate a user interface from a specification, or to guarantee…

forms-based programming

programming by filling out a set of forms that query a user about the types of inputs and results they want. Forms-based approaches are useful in specialized domains which do not require the full power and generalization of a traditional…

forward compatibility

designing software to work with future versions of itself, e.g. by anticipating the needs of future versions and how they will impact data formats and network protocols. For instance, in web development, writing HTML so that it will work in…

frame rate

the speed that an animation or video is displayed, specifically: the number of frames (individual pictures making up the animation or video) that are displayed per unit time. For instance, televisions display 60 frames per second (also called the “refresh…

frames

(website design) a technique for dividing up a window displaying a web page so that separate areas can scroll independently and load new pages independently.

Frames are useful when something needs to be on-screen all the time, such as navigation…

frankensteining

the merger of multiple designs into one despite the fact that they don’t form a coherent, consistent whole. A typical situation is to present multiple design options to a client who asks for a piecemeal combination of features. While the…

front end

the user interface portion of a piece of software; the portion of the software that faces the user; opposite of back-end, the underlying functionality of the application.

fundamental attribution error

the tendency for people to blame themselves rather than external factors for problems they have. In computer terms, the tendency to blame the user rather than the technology or its design when users have trouble with computers.