A Triadic Semiotics
Inspired by the computer metaphor and the developing field of linguistics (e.g., Chomsky), the main stream of cognitive science was framed as a science where mind was considered to be a computational, symbol-processing device that was evaluated relative to the norms of logic and mathematics. However, there were a few, such as James Gibson, who followed a different path.
Gibson followed a path that was originally blazed by functional psychology (e.g., James, Dewey) and pragmatist philosophers (e.g., Peirce). Along this path, psychology was framed in the context of natural selection and the central question was to understand the capacity for humans to intelligently adapt to the demands of survival. Thus, the question was framed in terms of the pragmatic consequences of human thinking (e.g., beliefs) for successful adaptation to the demands of their ecology.
An important foundation for Gibson's ecological approach was Peirce's Triadic Semiotics. In contrast with Saussure's Dyadic approach - Peirce framed the problem of semiotics as a pragmatic problem - rather than as a symbol processing problem. Saussure was impressed by the arbitrariness of signs (e.g., C - A - T) and the ultimate interpretation of an observer (e.g., kind of house pet). In contrast, Peirce was curious about how our interpretation of a sign (e.g., pattern of optical flow) provides the basis for beliefs that support successful action in the world (e.g., braking in time to avoid a collision). In addition to considering the observer's interpretation of the sign, this required a consideration of the relation of the sign to the functional ecology (e.g., how well the pattern specifies relative motion of the observer to obstacles - the field of safe travel), and the ultimate pragmatic consequences of the belief or interpretation relative to adaptations to the ecology (e.g., how skillfully the person controls locomotion).
The figure below illustrates the two views of the semiotic system. In comparing these two systems it is important to keep in mind Peirce's admonition that the triadic system has emergent properties that can never be discover from analyses of any of the component dyads. For Peirce the triad was a fundamental primitive with respect to human experience. Thus, arguing that the whole of human experience is more than the sum of the component dyads.
Mace's Contrast
William 'Bill' Mace provided a clever way to contrast the dyadic framework of conventional approaches to cognition with the triadic framework of ecological approaches to cognition.
The conventional (dyadic) approach frames the question in terms of computational constraints, asking:
How do we see the world the way we do?
The ecological (triadic) approach frames the question in terms of the pragmatic constraints, asking:
How do we see the world the way it is?
What Matters?
For a laboratory science of mind, either framing of the question might lead to interesting discoveries and eventually some of the discoveries may lead to valuable applications. However, for those with a practical bent, who are interested in a cognitive science that provides a foundation for designing quality human experiences, the second question provides a far more productive path. For example, if the goal is to increase safety and efficiency and to support problem solving in complex domains such as healthcare or transportation, then the ecological framing of the question will be preferred! You can't design either training programs or interfaces to improve piloting without some understanding of the dynamics of flight.
If the goal is to discover what matters in terms of skillful adaptations to the demands of complex ecologies, then a triadic semiotic frame is necessary. To understand skill, it is not enough to know what people think (i.e., awareness), it is also necessary to know how that thinking 'fits' relative to success in the ecological context (i.e., the functional demands of situations).