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affective computing
A future trend in computing in which computers appear to have emotions, and can sense user emotions. See also: autonomic computing, convergence, ubiquitous computing.

Links: Affective Computing Portal, Affective Computing at MIT Media Lab.

A relationship between an actor (i.e., person or animal) and an object; specifically, it refers to the possibility of the actor performing some action with the object, whether or not the actor can perceive that possibility. This term was introduced in J.J. Gibson's theory of ecological psychology, and later popularized (and misused) in Donald A. Norman's The Psychology of Everyday Things. See also: perceived affordance.

Links: More on Affordances, Gibson's Definition of affordance.

algebraic semiotics
The theory of signs as mathematical entities within formal sign systems. In algebraic semiotics, a sign exists in a semiotic space, is of a sort, is generated by a constructor, and satisfies all applicable axioms in the sign system of which it is a part. A mapping from one sign system to another is called a semiotic morphism. See also: semiotics.

Links: Algebraic Semiotics Homepage.

[alg. sem.] Concerning the deduction of the intended meaning of actual signs; the opposite of synthetic. Classical semiotics is analytic.

[alg. sem.] A function or predicate defined on signs of a certain sort. For example, an attribute of a graphical object might be its location within the computer display; such a function might return X and Y coordinates.

autonomic computing
A future trend in computing, inspired by the functioning of the human nervous system, in which computers are autonomous, self-repairing, transparent, and ubiquitous. See also: affective computing, convergence.

Links: Autonomic Computing at IBM.

[alg. sem.] A logical formula, built from constructors and attributes, that constrains the set of possible signs in a given sign system.

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classical semiotics
The field of study, developed by Peirce and Saussure, dealing with deducing the meaning of signs. See also: semiotics.

cognitive psychology
Area of psychology dealing with human cognitive processes; includes topics such as attention, perception, pattern recognition, memory, decision making, thinking, and problem solving.

[alg. sem.] A function that builds new signs of a given sort. A constructor can have parameters of any kind, including other signs. For example, a constructor for a GUI window might have parameters specifying the menus it will contain, and so on.

A future trend in computing in which computers merge with communications. See also: affective computing, autonomic computing, ubiquitous computing.

conversation analysis
A technique in ethnomethodology for studying how conversations are used in interaction, and how this brings about social organization.

Links: An Introduction to Conversation Analysis.

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Synonym for object or signified. See also: referent.

design space
[alg. sem.] A semiotic space of possible designs, generally constrained by the limitations of the medium in which the design is expressed. The "output" of a semiotic morphism is a sign system that describes signs in the design space.

[Peirce] See diagrammatic icon.

Links: [CD] diagram.

diagrammatic icon
[Peirce] An icon that shares geometrical structure with what it represents. See also: diagram.

diagrammatic iconic
[Peirce] Relating to or having the characteristics of a diagrammatic icon.

display sign
[alg. sem.] A sign in the design space that presumably represents a source sign in the source space.

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The study of the relationship between people and their working environment. Keeping in mind that different people possess different physical capabilities, its two principles are: fitting the person to the job, and fitting the job to the person.

Links: The Ergonomics Society.

The field of study, founded by the American sociologist Harold Garfinkel in the early 1960s, that investigates the ways in which people make sense of their social world; uses conversation analysis as one of its primary tools.

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A sign system (in the sense of classical semiotics) delimited by a collection of conventions for using a medium. For example, the graphical conventions of familiar GUIs constitute a genre within the medium of computer displays.

Acronym for Graphical User Interface. Pronounced "gooey".

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[Peirce] A "sign which refers to the Object that it denotes merely by virtue of characters of its own ... such as a lead-pencil streak as representing a geometrical line." See also: index, symbol.

Links: [CD] icon.

[Peirce] Relating to or having the characteristics of an icon.

Links: [S4B] iconic.

[Peirce] The property of being an icon.

[Peirce] A sign in which the representamen X is regularly connected to the object Y in the sense "that always or usually when there is an X, there is also a Y in some more or less exactly specifiable spatio-temporal relation to the X in question". A typical example is smoke as an index for fire. See also: icon, symbol.

Links: [CD] index.

[Peirce] Relating to or having the characteristics of an index.

Links: [S4B] indexical.

[Peirce] The property of being an index.

[Peirce] The mental effect of a sign on its interpreter; the sense made of the sign. See also: semiotic triad.

Links: [CD] interpretant, [S4B] interpretant.

iterative design
A design process with the following structure: 1) complete a portion of your design; 2) subject the completed portions of your design to user testing; 3) make changes to your design based on the user feedback; and 4) repeat steps 1-3 until done.

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[alg. sem.] A set of sorts at the same "tree depth" within a semiotic space. Sorts at a given level are constructed in terms of lower (or possibly the same, but not higher) levels. In modern GUIs, for example, one might take the entire display as the highest level sort, constructed perhaps from a background, windows, menus, icons, and a pointer, each of which is constructed from yet lower-level sorts, and so on. See also: constructor.

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A substrate for the transmission of signs, characterized by dimensions within which signs can vary. For example, a standard computer display is a two-dimensional surface with a grid of individually manipulable pixels; the illumination of each pixel is usually specified by a three-dimensional vector of values for red, green, and blue color brightness.

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[Peirce] What a sign refers to, stands for, or represents. See also: semiotic triad.

Links: [CD] object, [S4B] object.

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Pronounced "purse"; Charles Sanders Peirce (1839-1914) was an American philosopher, logician, and scientist. Peirce is known for being the primary founder of pragmatism, and the source of semiotics as a general theory of representation and interpretation.

Links: Commens: Peirce Studies Site.

perceived affordance
An affordance that an actor perceives as existing, whether or not that is actually the case. In UID, "real" affordances should map to perceived affordances as much as possible.

[alg. sem.] A partial ordering based on importance. If one constructor constructs the most important signs of a given sort, we call it the primary constructor for that sort. There may be other constructors with less priority, but constructors may also have equal priority (which is why in general the ordering is only partial). For example, there may be several constructors for text elements in a window; in particular, one whose parameters are capitalized words and whose value is a title might have higher priority than certain others because it constructs relatively more important signs.

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[alg. sem.] Of a semiotic morphism, the extent to which it preserves the structure of its source system. A high-quality semiotic morphism should map sorts to sorts, constructors to constructors, and so on while preserving levels, priorities, and axioms. Due to constraints in the design space, though, it is often impossible to preserve all such structure. For this reason and because priorities are subjective, one cannot expect there to be a single "best" semiotic morphism.

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recipient design
In ethnomethodology, the phenomenon that natural speech is always designed for its recipients.

Synonym for object or signified. See also: denotation.

[Peirce] The (not necessarily physical) form of a sign. See also: semiotic triad.

Links: [CD] representamen, [S4B] representamen.

[Peirce] A basic principle of semiotics; refers to a sign standing for something other than itself. In Peirce's words, "That character of a thing by virtue of which, for the production of a certain mental effect, it may stand in place of another thing. The thing having this character I term a representamen, the mental effect, or thought, its interpretant, the thing for which it stands, its object."

Links: [S4B] representation.

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Ferdinand de Saussure (1857-1913) was a Swiss linguist. He perceived linguistics as a branch of a general science of signs that he called semiology. Many of his ideas have since been included in what is now called semiotics.

[alg. sem.] Conceptually, the inverse of a constructor; a function whose parameter is a complex sign and whose value is one or more of the (lower-level) signs from which it was constructed. For example, a selector might take a menu as a parameter and "return" its first item.

[Saussure] The term used by Saussure to describe the science of signs and meanings. See also: semiotics.

[Peirce] An occurrence of meaning, involving the combination of all three parts of the semiotic triad.

Links: [CD] semiosis, [S4B] semiosis.

semiotic morphism
[alg. sem.] A mapping from a source system to a theory of display signs. One of the key ideas in algebraic semiotics is that semiotic morphisms can be compared based on their quality.

Links: Semiotic Morphisms.

semiotic space
[alg. sem.] The set of all signs possible in a given sign system.

semiotic triad
[Peirce] The representamen, the interpretant, and the object, and the relationships among them. See also: representation.

semiotic triangle
See semiotic triad.

Links: [S4B] semiotic triangle.

The study of signs.

Links: [S4B] semiotics.

In classical semiotics, anything interpreted as "standing for" something other than itself. In algebraic semiotics, a sign is an instance of a sort, and generally is the result given specific parameters of a constructor for that sort.

Links: [CD] sign, [S4B] sign.

sign space
[alg. sem.] See semiotic space.

sign system
In classical semiotics, particularly within the structuralist tradition, a sign system is a collection of related signs like those in a particular medium, genre, or language. In algebraic semiotics, a sign system is a theory; that is, a formal description (via sorts, constructors, axioms, and so on) of a semiotic space.

See token.


[Saussure] The meaning or concept represented by a signifier; what Peirce called the object.

Links: [S4B] signified.

[Saussure] The (not necessarily physical) form of a sign; what Peirce called the representamen. See also: signified.

Links: [S4B] signifier.

[alg. sem.] A kind of sign. A sort is analogous to a class in the object-oriented programming paradigm: a sign is of a certain sort just as an object is of a certain class. (Note: Do not confuse the notion of "object" in object-oriented programming with the notion of "object" in classical semiotics; they are different.)

source sign
[alg. sem.] A sign in a source space, usually with a corresponding display sign in the design space.

source space
[alg. sem.] A semiotic space that contains source signs to be represented in the design space.

source system
[alg. sem.] A sign system describing a source space; the "input" domain of a semiotic morphism.

A tradition within classical semiotics, beginning with Ferdinand de Saussure, focusing on the structure of systems of related signs rather than the referents of individual signs. For structuralists, meaning is relational: signs take on meaning only by virtue of their relations to other signs within a system. Treating these sign systems as "languages", they analyze complex signs by breaking them down into smaller meaningful units and identifying the relationships among them. Their goal is to find underyling structures, hopefully in order to understand the conventions governing production and interpretation of signs within systems.

Links: [S4B] structuralism.

[alg. sem.] A sort contained within another sort. For example, web browser windows are a subsort of GUI windows.

[Peirce] A "sign which is constituted a sign merely or mainly by the fact that it is used and understood as such." Symbols are signs merely by convention, having neither iconicity nor indexicality. For example, drive letters in MS-DOS and Windows (such as "C:") are symbols. See also: icon, index.

Links: [CD] symbol.

[Peirce] Relating to or having the characteristics of a symbol.

Links: [S4B] symbolic.

[alg. sem.] Concerning the production of signs intended to have certain meanings. Opposite of analytic. Design is synthetic.

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A configuration of matter and/or energy that may or may not be a sign; anything that does not necessarily convey meaning. Also referred to as a signal.

A goal of user interface design in which the interface becomes "invisible", and the user can focus on the task at hand. For example, skilled computer users can use a mouse to move a pointer and perform operations, without thinking about how the mouse is moving the pointer. Transparency breaks down when the interface breaks down; for instance, if the mouse ball collects dust and the pointer movement becomes erratic.

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See ubiquitous computing.

ubiquitous computing
A future trend in computing in which computers will be everywhere. See also: affective computing, autonomic computing, convergence.

Acronym for User Interface Design.

user interface design
In semiotic terms, the process of synthesizing a configuration of signs that will enable a user to perform some practical task.

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©2003 Dana Dahlstrom and Vinu Somayaji. All rights reserved.
Last modified: Tue, 10 Jun 2003 20:24:37 -0700.