| abstraction : | A term in a notational system or other information artifact that is defined with reference to the primitive concepts of the system, or with reference to other abstractions that are ultimately defined by primitives. It is frequently used to aggregate many instances, so that all can be manipulated by a single action; thus, a heading style is a typical word-processor abstraction defined in terms of font properties, and all its instances can be altered by altering its definition. |
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| abstraction hierarchy : | A hierarchical description of the functional structure of a work domain, in which work-domain purposes are related to underlying physical structures. Also referred to as a structural means-ends hierarchy because links between adjacent levels connect ends (upper nodes) to means (lower nodes). |
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| ACT-RPM : | The latest in a series of computational cognitive architectures developed by John Anderson and colleagues. ACT-RPM contains architectural mechanisms for cognitive, perceptual, and motor performance and learning. It was one of the architectures reviewed in Pew & Mavor (1998). More information about this series of architectures can be found in Anderson (1976, 1983, 1993) and Byrne & Anderson (2001). |
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| activity : | The significant and typically collective endeavors of humans. It is the fundamental concept in activity theory, which conceives of activity as conducted through individual actions and mediated by artifacts. In the cognitive-dimensions framework, an activity is likewise a significant endeavor conducted through individual actions, but six generic types of activity are distinguished (e.g., search, design, etc.); at present, only individual interaction with information artifacts is considered. |
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| adaptationism, adaptationist approach : | The thesis that selection pressures have been the most powerful cause of evolution; a useful methodological heuristic is to assume that biological and behavioral structures are the results of adaptation to the environment. |
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| affordance : | Perceptual characteristics of an object that make it obvious what the object can do and how it can be manipulated. |
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| anthropology : | The investigation of social structure, social relationships, and individual social action through an emphasis on culture—originally “other cultures” but increasingly the emphasis is on “home” cultures. |
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| apex : | A computational architecture using resource scheduling and reactive planning (techniques from artificial intelligence). More information can be found in Freed (1998). It has been used as a GOMS modeling tool (John, 2002; Remington, et al., 2002). |
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| artifacts : | A diverse class of human-created systems, applications, tools, and conventions, including language and mathematics, that mediate human activity. Artifacts are the products of prior human activity; they both enable and constrain current human activity, and their use helps to orient the design of future artifacts. An information artifact (as used in the cognitive-dimensions framework) is an artifact designed to store, create, present, or manipulate information, whether noninteractive (e.g., a book or a map) or interactive (e.g., a spreadsheet or a heating controller). |
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| automatic cognitive processes : | Processes that are relatively quick and effortless, requiring little attention or monitoring. Well-practiced skills, like walking and driving, or signing one’s name, are examples of automatic cognitive processes. See also controlled cognitive processes. |
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| bounded rationality : | The idea, from Herbert Simon (e.g., Simon, 1982), that human agents are rational in that they act so as to meet their goals according to their knowledge; they are only boundedly rational, however, in that they cannot necessarily compute ideal, optimal decisions. Instead, their decisions are bounded by environmental constraints on their performance (such as the need to act quickly), interacting with limits on access to knowledge and limits on the ability to process relevant information. |
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| claims analysis : | An analytic evaluation method involving the identification of scenario features that have significant positive and negative usability consequences. |
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| claims feature : | An element of a situation or an interactive system that has positive or negative consequences for people in this or similar situations. |
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| CMN-GOMS : | The original version of GOMS created by Card, Moran, and Newell (1980a). The “CMN” was added before “GOMS” when other versions of GOMS began to appear (e.g., CPM-GOMS and NGOMSL), to differentiate the specific representation used by Card, Moran, and Newell from the concepts in GOMS. |
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| cognitive architecture : | The fixed structure that realizes a cognitive system. It typically decribes the memories and processors in a cognitive system and how information flows between them. This is in contrast to the knowledge laid on top of an architecture to allow it to perform a task in a particular domain. |
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| cognitive artifact : | A manmade or modified tool to support mental activity. Examples include number systems, slide rules, navigational charts, and even language itself. While generally applied to a single individual, within the framework of DCog, a cognitive artifact is also a tool that supports the coordination of information processing between entities within a functional system. |
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| cognitive complexity theory (CCT) : | A computational cognitive architecture introduced by Kieras and Polson in the 1980s and used as the basis for NGOMSL. It was realized in a production system. More information can be found in Bovair, Kieras, & Polson, 1988, 1990; Kieras & Polson, 1985. |
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| cognitive dimension : | A characteristic of the way information is structured and represented—one that is shared by many notations and interaction languages of different types and, by its interaction with the human cognitive architecture, that has a strong influence on how people use the notation and determines what cognitive strategies can be pursued. Any pair of dimensions can be manipulated independently of each other, although typically a third dimension must be allowed to change (pairwise independence). (More exactly, a cognitive dimension is not solely a characteristic of the notation, but a joint characteristic of the notation and the environment in which the notation is used, whether based on paper and pencil or computer or even based on voice and sound.) Examples such as viscosity, premature commitment, and others are defined in the text. Note that in the cognitive-dimensions framework, dimensions are not evaluative per se, but only in relation to a particular type of activity; for example, viscosity is a problem for modification activities but not for transcription activities. See also cognitive-dimensions. |
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| cognitive engineering : | A multidisciplinary area of research concerned with the analysis, modeling, design, and evaluation of complex sociotechnical systems. It is sometimes also called cognitive systems engineering. |
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| cognitive ethnography : | A qualitative method of data collection used by DCog researchers based around observation. It is “cognitive” because it focuses on computational information transformations within a functional system. |
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| cognitive science : | The scientific project dedicated to understanding the processes and representations underlying intelligent action. |
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| cognitive-dimensions framework : | This states the pertinent values of cognitive dimensions that are required to support a given type of activity, and thereby provides a means to evaluate an information artifact. |
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| cognitivism : | Maintains a Cartesian dualism, attributing human conduct to the operation of mental predicates. Often associated with a computational theory of mind, it is a predominate paradigm within human-computer interaction (HCI). |
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| conceptual framework : | A structure describing the concepts in a cognitive system, less specific than a cognitive architecture. |
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| constraints : | In the context of cognitive work analysis, factors that limit, but do not prescribe, how effective work activity might be carried out. |
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| control task analysis : | A way of analyzing work that focuses on the control that must be exercised over a work domain and the tasks implied to exercise such control. An analytic phase of cognitive work analysis. |
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| descriptive model : | A model that describes how a system or person behaves and that provides a framework or context for thinking about or describing a problem or situation. Usually based on data gained through empirical observation, it is often little more than a verbal or graphic articulation of categories or identifiable features in an interface. |
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| design : | Encompasses activities and actions directed at producing new artifacts. Design work is collective and multidisciplinary. It often includes professional designers, technologists, and future users of the artifacts. |
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| design rationale : | Arguments for why (or why not) a feature or set of features should be incorporated into a design. |
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| ethnography : | Originating in the anthropology of Bronislaw Malinowski, this has come to mean the study of cultural and societal matters from inside their operations. It is associated with fieldwork, which emphasizes the importance of participatory methods for collecting data about social phenomena. |
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| formalism : | A philosophy or practice that focuses on the manipulation of surface representations or symbols with a disregard for the underlying semantics and meaning. This may be as a strong philosophical stance or it may be because it is believed that, in a certain situation and for a particular end, the symbols capture faithfully the underlying meaning. |
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| formative model : | A model that identifies requirements that must be satisfied so that a system can behave in a new, desired way if needed. |
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| functional system : | The functional system is the unit of intelligent activity that is analyzed in DCog; it may be composed of a collection of any number of individuals and artifacts. It is bounded by the problem, and it includes all of the entities that compose the problem space and which are involved in problem solving. |
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| goals : | The “G” in GOMS, goals are what the user is trying to achieve through interaction with the computer system. |
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| GOMS : | GOMS is an analytic technique for making quantitative and qualitative predictions about skilled behavior with a computer system. The acronym stands for goals, operators, methods, and selection rules. |
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| hidden dependencies : | Important but invisible links between entities in the cognitive dimensions framework. Frequently the links are visible in one direction but not in the other (cell dependencies in spreadsheets, for example). See the text for more details. |
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| information processing : | Within cognitive science, problem solving is seen as an information-processing activity [See computational metaphor (of cognition)], in which encoded information is acted on and transformed in the resolution of a goal held by a cognitive entity. |
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| information visualizations : | The use of computer-supported, interactive, visual representations of abstract data to amplify cognition. |
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| interaction language : | The commands used to instruct an interactive information artifact such as a word processor or a heating controller. These commands are a form of notation, but typically what the user can see as feedback is the effect of the command rather than the command itself. For example, in a word processor’s interaction language, giving the command Delete Word deletes a word; in the same word processor’s macro language, however, giving the same command Delete Word inserts the appropriate symbols into a program. See also notation. |
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| joint action : | Both people involved in a joint action intend to do their part and believe that the joint action includes their and the other person’s part. (See the text for a more formal and comprehensive definition.) |
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| keystroke-level model (KLM) : | The simplest GOMS technique. It provides standard keystroke-level operators (D, H, K, M, P, and R) with estimates of duration and rules for placing the M (mental) operators. It abstracts away from the goal hierarchy, multiple methods, and selection rules found in other GOMS techniques. More information can be found in Card, Moran, and Newell (1980b, 1983). |
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| learning as development : | A view of learning that emphasizes the triggering and maturation of skills (versus their acquisition through practice). Some versions construe this as biologically prefigured (Piaget), and others construe it as socially mediated (Vygotsky). In this view, people are not understood not only in terms of what they are but in terms of what they are becoming. |
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| mediated communication : | Human-to-human communication may be mediated by technology—for example, by telephone or video phone, by text chat, or by email. |
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| mental model : | A cognitive structure of concepts and procedures that users refer to when selecting relevant goals, choosing and executing appropriate actions, and understanding what happens when they interact with a computer system (or other tool). |
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| methods : | The “M” in “GOMS,” methods are well-learned sequences of subgoals and operators that can accomplish a goal. There may be more than one method to accomplish a goal. If so, then selection rules are used to determine which method to use in the current task situation. |
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| model : | An simplified expression of reality that is helpful for designing, evaluating, or understanding the behavior of a complex artifact such as a computer system. |
| | model human processor (MHP) : | The information-processing cognitive architecture introduced by Card, Moran, and Newell in 1983. It was never realized in a computational form, but it sufficiently specified its memories, processors, communications, and principles of operation that some quantitative predictions of human behavior could be derived. The MHP was merged with GOMS through CPM-GOMS. |
| | motor control : | A branch of experimental psychology concerned with the study of human movement. |
| | MUD(multi-user domain) : | A persistent collaborative environment that is modeled on a geographic space. |
| | nonfunctional requirements : | Qualities of a system under development that are not directly related to its function, such as maintainability or reliability. |
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| notation : | A system of symbols used in specialized fields to represent facts or values (as in a circuit diagram) or to give instructions (as in a programming language), usually subject to rules of combination and ordering (“syntax”). Although the symbols are discrete, there may be an admixture of analog features (relative placement of components in a circuit diagram, or layout of text in a program). This is a wider definition than that of Nelson Goodman’s (1968), for example, but it is more typical of conventional usage. Notations may be persistent (written down) or transient (spoken or otherwise fleeting). See also interaction language. |
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| operator : | The “O” in “GOMS,” operators are the actions that the software allows the user to take. Operators can be defined at many different levels of abstraction, but most GOMS models define them at a concrete level, like button presses and menu selections. |
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| participatory design : | A design movement primarily associated with Scandinavia, in which future users of the artifacts being designed participate in the original design work. |
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| PIE model : | An example of an abstract formal model—that is, one that is used to analyze a class of systems and usability problems rather than specifying a particular system. The PIE model was developed at York University in the mid-1980s and was one of the first steps in a new stream of formal method work in human-computer interaction (HCI) that began at that time. See: http://www.hcibook.com/alan/topics/formal/ |
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| problem solving : | Searching through a problem space from a known start state to a desired end state, or one of a set of desired end states, applying operators of uncertain outcome to move from state to state. Problem solving typically refers to a path through the problem space that includes explorations of deadend paths and backing up to prior states. (see skilled behavior for a contrasting type of behavior) |
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| problem space : | A mental representation of a problem, including the start state, the goal state, and the operators or moves that allow transitions between states. According to Newell and Simon’s (1972) theory of problem solving, humans solve problems by constructing and searching a problem space. |
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| procedural knowledge : | Also called “how to do it” knowledge. The knowledge of which operators to perform to move from a known start state to a desired state in a problem space. |
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| progressive evaluation : | In the cognitive-dimensions framework, the ability to review or test a partially complete structure, to check on progress to date it is important for novices, and becomes less so as one gains experience. Some systems allow only a complete design to be reviewed; others allow a review at any stage. |
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| propositional representations : | Representations that have a more-or-less arbitrary structure; for example, a word or a sentence in a natural language. See also analog representations. |
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| representation : | This can be seen as encoded information, either as a symbolic abstraction of a thing (classical cognitive science), or as a distributed set of nodes (PDP) that, together, have meaning. According to the representational theory of mind, human brains operate on symbolic representations, or codes. DCog extends this to show how transformations to representations need not be entirely symbolic, but may be enacted through manipulations on physical media that have a representational status (e.g., a navigational chart or a drawing). |
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| scenario : | A narrative or story that describes the activities of one or more persons, including information about goals, expectations, actions, and reactions. |
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| selection rules : | The “S” in GOMS, selection rules are the rules people use to choose between multiple methods that accomplish the same goal. They typically depend on characteristics of the task or user’s personal preferences or knowledge. |
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| situated action : | One can plan to descend a set of rapids in a canoe, and one can plan and replan as one goes along, but one cannot (successfully) plan the descent and then merely execute the actions. Suchman, in her 1986 book “Plans and situated actions”, analyzed action as necessarily improvisational. Actions are undertaken in response to the constantly changing physical and social environment. An important consequence of this is to make plans and planning a resource for action, and not simply as the determinant of action. |
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| situation model : | A mental model derived from a text that represents what the text is about. |
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| skilled behavior : | Movement through a problem space by applying a known operator at every state, from a known start state to a known end state. (see problem solving for a contrasting type of behavior). |
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| social-organizational analysis : | A way of analyzing work that focuses on how work is organized and shared across people and supporting tools. It is an analytic phase of cognitive work analysis. |
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| sociology : | The investigation of social structure, social relationships, and individual social action. |
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| strategies analysis : | A way of analyzing work that focuses on different ways that a particular control task might be carried out. An analytic phase of cognitive work analysis. |
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| symbolic interactionism : | Originated in the social psychology of George Herbert Mead and the sociological methodology of Herbert Blumer, this places emphasis on the individual in explanations of the transactions of people and society. |
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| task analysis : | Any process that identifies and examines tasks that must be performed, either by users, other agents, or the system itself, to accomplish the goals of an interactive system. |
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| tradeoff : | An issue (often in design) that is understood to have competing arguments, usually positive and negative impacts of an option. |
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| transfer of learning : | A learning and memory phenomenon in which what is learned in one situation facilitates understanding and behavior in a similar situation. |
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| use/users : | Many human activities incorporate computer applications. In human-computer interaction (HCI), the terms use and users are applied to the common properties of computer applications in work activity, and to the people who use computer applications as part of their daily practice. These terms are somewhat unfortunate, as the people rarely construe their own activity as computer use per se or see themselves primarily as users of computer equipment. |
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| visibility : | In the cognitive-dimensions framework, this is the ability to view components easily whenever necessary. See also juxtaposability. |
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| visual working memory : | A limited-capacity visual store that is distinct from verbal working memory. It is a core component of modern cognitive theory. |
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| work-domain analysis : | A way of analyzing work that focuses on identifying the functional structure of the work domain with which a human operator will interact (rather than identifying tasks to be performed in the work domain). An analytic phase of cognitive work analysis. |
| | worker-competencies analysis : | A way of analyzing work that focuses on the cognitive competencies required of or evident in workers, given their training, expertise, and the way information is represented to them. An analytic phase of cognitive work analysis. |
| | yoked-state space hypothesis : | The claim that users of representational devices (such as computer systems) need to mentally represent the device itself, the domain to which the device refers, and the way in which the device represents the domain. See Payne, Squibb, and Howes (1993). |
| | zero-parameter models : | Models that can make a priori predictions of quantitative performance of users on an interactive system. The are called zero-parameters because no parameters need to be set from data collected on the system in question; all numeric parameters can be set through a task analysis and pre-existing data from prior research. |
| | zone of proximal development : | The inventory of capabilities people can currently demonstrate with assistance (human and material support) and therefore may, in the future, be able to achieve by themselves. |
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