When I began thinking seriously about affordances, I often stated that the concept was undertheorized. This is a common declaration from scholars who write about the topic, and it was appealing to me as a justification for my own work. If affordances were undertheorized, then perhaps I could make a meaningful and substantial contribution to the field. The claim also seemed empirically true. There are reams of academic texts that use the term affordance as a central analytic device but provide no definitions, further explication, or serious attention to its theoretical underpinnings. Yet the more I read, the less comfortable I became with my own assertion.
As I came to discover, the scholarly treatment of affordances has been extensive and sophisticated. I found myself buried under piles of literature, much of which is painstaking and detailed. Specific relationships between artifacts, subjects, and environments have been formalized through numeric equations, careful nomenclature, graphs, charts, arrows, and appendices. Debates have been robust, and word counts expansive. Affordances are, in short, very theorized. At the same time, however, there remains definitional confusion, conceptual looseness, and an oddly accepted convention of using the concept as though it has no intellectual history at all.1
Paradoxically, the affordance theoretical literature is dense and unwieldy, and yet in practice, it is apparently ignorable. I wonder whether this contradiction is more than just a fluke. The strength of affordance as a concept is its efficient manner of expressing technological efficacy without falling into determinism. Its beauty is in its parsimony. A theoretical trajectory that overspecifies affordances and related conceptual variables (including artifacts, environments, organisms, users, designers, and architectures) may obscure, rather than reveal, the concept’s full potential. Disciplinary jargon doesn’t help, either.
After immersing myself in fifty years of affordance literature, I now contend that the concept needs not more theory but smarter theory. Affordance needs a theoretical treatment that does justice by its richness and depth while maintaining the simplicity that makes the concept an elegant and practical tool. This is my aim with the mechanisms and conditions framework, presented in chapters 4 and 5. To get to the framework, the first task is to lay out and untangle affordance’s conceptual history. Such a project sets the foundation for my own conceptual model and also highlights the rigorous and thoughtful work that already exists, bringing together multiple threads into a legible and coherent whole. This chapter offers a foray into the main ideas, debates, and applications of the concept since its inception in the 1960s. Rather than a complete catalog of affordance references, I focus on the most influential pieces and those that most clearly demonstrate relevant lines of thought. This is not an exhaustive literature review but a narrative about where affordances have been and how they can be mobilized for both analytic and practical purposes.
James J. Gibson first introduced affordances as the pinnacle concept in his work on direct perception.2 An ecological psychologist, Gibson departed from the dominant perspective of the time, which emphasized representation and inference. Rooted in the ideas of nineteenth-century German scientist and philosopher Hermann von Helmholtz, psychologists in the 1960s predominately modeled perception as a three-term system.3 The three-term model of perception assumes that perception is the function of a subject, an object, and a mediated representation. For instance, a person (subject) sees a tree (object) via a representational image on the retina (mediator). The subject uses existing knowledge to disambiguate the mediated image and make sense of it.
Gibson rejected this representational perspective in favor of a two-term model that includes only objects and subjects (or as Gibson would say, environments and organisms).4 The representational model was referred to as inferential perception, whereas Gibson was interested in direct perception. Inferential perception requires that representations are disambiguated via subjects’ existing knowledge. Gibson argued that subjects do not need existing knowledge of a situation to disambiguate but instead can perceive directly from the environment and act based on direct perception. That is, the predominant view of perception at the time was inferential and representational. In contrast, Gibsonian perception was direct, antirepresentational, and action-based.5
The concept of affordance was central to Gibson’s thinking. In 1966, Gibson first defined affordances as “what things furnish, for good or ill.”6 A decade later in his now canonical text The Ecological Approach to Visual Perception, Gibson expanded the definition:
The affordances of an environment are what it offers the animal, what it provides or furnishes, either for good or ill. The verb to afford is found in the dictionary, but the noun affordance is not. I have made it up. I mean by it something that refers to both the environment and the animal in a way that no existing term does. It implies the complementarity of the animal and the environment.7
For Gibson, affordances are action-based, dynamic, and necessarily relational. Perception is a direct dispositional relation between objects and subjects in which opportunities for action are the driving force. For instance, Gibsonian affordances are not concerned with the Euclidian space between points but instead with the distance between points in relation to a subject’s stride.8 “[W]hat we perceive when we look at objects are their affordances, not their qualities,” says Gibson.9
Gibson’s ideas stem from gestalt psychologists who were working in the 1930s, especially Kurt Lewin and Kurt Koffka, who were interested in perception and sensemaking as greater than the sum of individual parts.10 For instance, Koffka describes mailboxes as having a “demand-character” for those seeking to mail a letter. That is, the mailbox is not just its material elements, but the materialization of an action opportunity for a subject in need. Gibson builds on this by arguing that affordances are action opportunities that derive from a relationship between properties of objects and properties of subjects, regardless of the subject’s need or propensity.
Gibson’s conceptualization of affordance has two critical elements: objectivity and bidirectional relationality. Affordances are opportunities for action, based on both intrinsic properties of objects and their relation to subjects. That is, affordances are opportunities for action, not necessarily their actualization. As Gibson explains, “an affordance is not bestowed upon an object by the need of an observer and his act of perceiving it. The object offers what it does because of what it is.”11 Of postboxes and letter writing, Gibson says:
For Koffka, it was the phenomenal postbox that invited letter-mailing, not the physical postbox. But this duality is pernicious. I prefer to say that the real postbox (the only one) affords letter-mailing to a letter-writing human in a community with a postal system. This fact is perceived when the postbox is identified as such, and it is apprehended whether the postbox is in sight or out of sight (emphasis in original).12
For Gibson, affordances are not predicated on use but are manifest in relation to socially situated subjects. Objects and subjects are therefore co-constitutive, and affordances are potential actions arising from bidirectional object-subject relations.
Gibson’s concept of affordance became significant in the psychology of perception. Since then, it has branched fruitfully into a diverse range of fields, where it remains influential to this day. Key expansions have taken hold in design studies and human-computer interaction, anthropology, engineering, communication studies, and education with a focus on pedagogy and technology.
The first major shift in affordance theory came in 1988, when Donald A. Norman introduced the idea of affordances to design studies and human-computer interaction (HCI). Norman’s eminent work The Psychology of Everyday Things (POET) contends that objects should be designed in ways that guide users’ perceptions and thus guide action.13 For Norman, an effective designer should also be an insightful psychologist who builds objects in ways that direct users along intentional pathways. He recognizes that objects have multiple affordances and calls on the designer to highlight desired and relevant action opportunities. Norman first defined affordance as follows:
The term affordance refers to the perceived and actual properties of the thing, primarily those fundamental properties that determine just how the thing could possibly be used. A chair affords (“is for”) support and, therefore, affords sitting. A chair can also be carried.14
Norman eventually renamed his germinal work from The Psychology of Everyday Things to The Design of Everyday Things (DOET).15 Not only does the updated version have a new title, but it also presents new theoretical delineations that attend to critiques against the original text.
In its original formulation, Norman’s POET emphasizes perception, in contrast to Gibson, who speaks of the inherent properties of an environment. Critics argued that Norman’s formulation gives short shrift to materiality. It is too subjective, they said, and does not grant enough efficacy to material conditions.16 A decade later in DOET, Norman addresses this point by distinguishing between “real” affordances and “perceived” affordances. Real affordances are the actions that an environment makes available, and perceived affordances are those that the user knows are available. He argues that this is a key distinction and that designers should focus on the latter.
In the updated text, Norman envisions object-subject interactions as a series of distinct constraints. He differentiates between cultural constraints, physical constraints, and logical constraints. Physical constraints are synonymous with affordances, logical constraints are what the design environment makes readily available, and cultural constraints are norms shared by a group. Referencing cultural constraints, he further differentiates between affordances (real and perceived) and conventions. Conventions are cultural constraints that have evolved over time, encouraging some actions while inhibiting others. He summarizes the updated argument as follows:
Affordances specify the range of possible activities, but affordances are of little use if they are not visible to the users. Hence, the art of the designer is to ensure that the desired, relevant actions are readily perceivable.17
Gibson and Norman both convey an image of objects and subjects in relation. However, their work derives from distinct disciplinary traditions, each maintains unique purposes, and each diverges from the other in the primacy of objectivity (Gibson) and subjectivity (Norman). Norman’s distinction between real and perceived affordances works toward reconciling the two formulations, but daylight remains between these foundational statements on the concept. Drawing variously from Gibson and Norman, the concept of affordance has found its way into myriad fields outside of psychology and HCI. Indeed, disciplinary expansion of the concept appears in anthropology, engineering, communication studies, and education, with threads seeping into neuroscience, robotics, sociology, and philosophy.
Although affordance’s interdisciplinary spread has resulted in a dense and at times unruly literature, it also demonstrates the potential for the concept as an analytic tool that spans disciplinary boundaries. Such tools are critical in a historical moment marked by rapid social and material change. Contemporary problems are increasingly beyond the scope of singular disciplinary expertise. Yet true interdisciplinary collaboration is often stifled by distinct languages and conventions that create barriers to communication and understanding. A concept that has organically traveled from one discipline to the next demonstrates strong potential as an intellectually unifying force.
Anthropologists have adopted affordance as a means of cross-cultural understanding and analysis.18 By rejecting the assumption that humans are distinct in their reliance on symbols and accepting instead the premise of direct perception, anthropologists can learn about new cultures through shared perception (the affordances of shared place and space) and can analyze cultures outside of their own without the troubling distinction between “us” and “them.” Tim Ingold explains:
The argument, in a nutshell, was that a relational approach to affordances might give us a language in which to express how people continually bring forth environments, and environments people, that could escape the endlessly self-replicating dualism between a universally given world of nature and the diversely constructed worlds of culture.19
In this vein, Bryan Pfaffenberger advocates for affordance as a conceptual means to capture the tridimensional relationships between technique, sociotechnical systems, and material culture.20 Through affordances, anthropologists have a dynamic way to understand the interplay between the resources with which artifacts are made (skills, knowledge, and tools), the sociotechnical systems that link cultural practices with technological developments, and the tangible material culture that results from and cycles back to inform cultural praxis. Thus, an anthropological observation of public transit behavior in Beijing would account for the interplay of urban infrastructure, population density, and cultural sensibilities as cocreating both objects (trains, platforms, buses, and share bikes) and subjects (commuters, tourists, and private motorists). The affordance perspective gives the anthropologist an analytic lens with which to understand people and culture in context.
In engineering, Jonathan R. A. Maier and George M. Fadel have led the field in constructing an affordance ontology and method of implementation.21 Their affordance-based design (ABD) introduces affordances as fundamental to engineering design and defines affordance as the relationship between two subsystems in which potential behaviors can occur that would not be possible with either subsystem in isolation. ABD incorporates four basic elements: artifacts, users, environments, and designers. Affordances are the relationship between artifacts, users, and environments. The job of the designer is to optimize the intersection of these three elements toward some defined goal or goals. This resonates with Norman’s original call for adequate “mapping,” in which designers are tasked with psychological insight as they build technologies that clearly guide users down intended paths. As a simple example, chest-height desks facilitate standing, and waist-height desks are primarily suited for sitting. The former guides users down a “healthy” and active physical relationship to the workspace, whereas the latter guides users toward stagnation. An active stance is thus likely preferable if the goal is health and wellness. A sedentary disposition may be preferable if the goal is long stretches of uninterrupted productivity. With an affordance frame, engineers can design with these (and other) various goals in mind.
Within communication studies, affordance has emerged as a robust concept in the study of information communication technologies (ICTs) and computer-mediated communication (CMC). Affordance is useful for its capacity to capture the ways hardware and software interact with socially situated users.22 Affordance research in communication studies shows how digital architectures, infrastructures, policies, and practices shape and reflect social dynamics. Hence, a review of affordances in the ICT/CMC literature shows studies variously emphasizing design architectures,23 individual user practices,24 platform policies,25 and informal conventions.26
Digital and electronic media have also driven the conceptual use of affordance in studies of education and pedagogy.27 Scholars contend that educational technologies interact with learners to construct learning environments with greater or less pedagogical value. For instance, Roy D. Pea utilizes affordance to conceptually describe the interplay between students and technical systems in a distributed learning environment.28 Diana Laurillard and colleagues contend that affordances can shape the relative learning benefits for experts and novices in diverse learning groups.29 Daniel D. Suthers explores how learning goals can be designed into technical systems,30 and Grainne Conole and Martin Dyke tease out the criteria for technological affordances that enable collaborative learning.31
In short, affordance has conceptual legs, and those legs have traveled. The concept now spans multiple fields and does diverse and important analytic and practical work. The immense breadth of a single concept speaks to its hardiness. And yet the concept has not been without controversy. Indeed, the affordance literature is thick with debate and critique, much of which revolves around various emphases on objects, subjects, and contexts.
Since Gibson introduced affordances in the 1960s, the literature has been active with debates about the primacy of subjects versus objects and about the role of context and culture in affordance analyses. Gibson’s antirepresentational direct perception approach positioned affordances as bidirectional relationships between “organisms” and “environments.” However, some interpret his definition (“what things furnish, for good or ill”) as a model in which environments have disproportionate weight while organisms respond only to environmental stimuli. In contrast, critics point to Norman’s conceptualization as overly perceptual, unable to adequately attend to material features outside of what subjects perceive. Debates within the affordances literature thus posit various ways to portray object-subject dynamics most precisely. Moreover, analysts contend that neither Gibson nor Norman fully account for contextual and cultural factors. Critics thus build on early works by advancing models of affordance that situate objects and subjects within sociostructural conditions.
Although Gibson’s conceptualization of affordance is ontologically bidirectional, defined as a relation between environments and organisms, his work is largely concerned with how the environment emerges as directly perceivable. Thus, his work has been interpreted as maintaining an emphatic bias toward objects rather than subjects.32 Seeking to rectify Gibson’s materialist leanings, the psychologist William H. Warren recentralized subjects in affordance analysis through a case study of stair climbing.33 Warren set out to determine the relational properties that make stairs unclimbable, climbable, and optimally climbable for distinct subjects, so he quantified the relationship between leg length and riser height as a metric for stair climbability. Not only did Warren show how the properties of objects (riser height) and properties of subjects (leg length) exist in relation, but he also demonstrated subjects’ active perception when interpreting the objects with which they engage. Warren’s subjects showed remarkably accurate perception of the ease or difficulty with which they would be able to climb a set of stairs, indicating the relevance of perception in object-subject relations. Warren’s case study remains a quintessential example of affordance relationality that contemporary theorists continue to evoke.
A group of philosophers built on similar ideas to those advanced in Warren’s stair study and introduced effectivity as a conceptual way to balance out Gibson’s theorizing.34 Effectivity was set up as a complementary concept that emphasizes subjectivity in perception and the capacity to act. Thus, “The animal’s effectivities are directed to the environment in the way that the environment’s affordances are directed to the animal.”35 The effectivity-affordance duality ensures equal and dynamic relations between subjects and objects.
Although effectivity deals with the issue of relationality, critics contend that it undermines the power of Gibson’s concept, which explicitly entwines environment and subject. Constructing two complementary concepts (affordance and effectivity) thus undermines affordance’s bidirectional quality, which is its most crucial feature.36 Nonetheless, the effectivity-affordance duality maintains purchase within ecological psychology and was formalized by Michael Turvey with a focus on actualization. Turvey contends that affordances are not ontologically present in the environment and that effectivities are not ontologically present in the subject. Rather, affordances are actualized through the match between particular object affordances and subject effectivities.37
Another conceptual distinction that has emerged is between utility and usability.38 This is an effort to capture the materiality of Gibsonian affordances while addressing the perceptual focus of Norman’s work. The utility of an object refers to its potentialities in relation to subjects, while usability refers to the perceptual information signaled to the subject by the object. A similar distinction has been introduced in engineering through the complementary relationship between functions and affordances.39 Functions are those features designed into an object, while affordances are the “totality of behaviors the user can perform with it.”40 Again, we see a relationship between material potentialities and subjective perceptions that affect—but do not determine—actions and outcomes. These ideas are further expanded as theorists take on the additional variable of context.
In addition to efforts toward reconciling objects and subjects in affordance analyses, theorists have also endeavored to account for context. Anthony Chemero contends that in order for an affordance to actualize, there must be a fit between the properties of the object and the properties of the subject, along with circumstances that support perception and enactment.41 In this way, a meshing of object and subject does not determine an outcome but generates a potentiality that can change across time, between subjects, and amid new circumstances. From this perspective, the “affordances of technological objects are not reducible to their material constitution but are inextricably bound up with specific historically situated modes of engagement and ways of life.”42 Building on this, Andrea Scarantino distinguishes between surefire affordances and probabilistic affordances. Surefire affordances manifest in a certain outcome, and probabilistic affordances have a positive probability of less than 1.43 That is, under certain conditions, we can expect objects to elicit a predictable and certain response (surefire), and in other conditions, the environment will push in one direction, but outcomes are not inevitable (probabilistic).
Tied up with contextual factors is the social element of technological artifacts. Neither objects nor subjects exist in isolation. Rather, objects and subjects are part of a world that is “propertied by other people”44 and by other things.45 Capturing the social element, the term social affordances theorizes an intersubjective relation between persons in situations that shape the meanings, perceptions, and affordances of physical objects.46 Richard C. Schmidt demonstrates social affordances using the example of a cup with a handle. The cup takes on one meaning as an object for purchase in a store and yet another when given as a gift. It thus affords grasping, filling, and drinking-out-of but also affords capitalist exchange, relationship building, and memory making.47 In this vein, organizational affordances capture the ways organizational bodies interplay with technical systems to shape one-to-many and many-to-many interactions and relational dynamics.48
Summarily, Gibson originally conceived affordances as something that “cuts across” object-subject relations. Norman then applied the concept to HCI, merging the roles of designer and psychologist. The concept was and remains influential. However, analysts found early formulations unsatisfactory in their overemphasis on either materiality or perception. Attempts to rectify the issue generated complementary concepts such as effectivity, function, and utility and usability, all of which capture the relevance of perception and its imbrication with materiality as affordances take shape and animate action. The role of context has also risen to the fore with contentions that objects and subjects are enabled and constrained through cultural conventions, social relationships, and situational factors that shape meaning and action opportunities.
Affordance has enjoyed conceptual longevity and proven analytically useful across multiple disciplines. Despite or perhaps because of this, the concept has also endured sustained patterns of critique. Three main critiques are leveraged against the concept of affordance: definitional confusion, binary application, and failure to account for diverse subjects and contexts. As demonstrated in the section above, analysts have certainly worked to address each of these issues. However, the critiques have yet to be resolved in a systematic or widely applicable way.
If you speak with people who study affordances, there is a high probability that they will lament the concept’s misuse, overuse, and entirely undefined use within academic literatures. The problem of definitional confusion in affordance analyses is polemic. On the one hand, the concept has been reformulated to death and tied to increasingly specific disciplinary jargon. On the other hand, the concept is often used without any definition at all, as though it has no intellectual roots or any controversy about its meaning.49
The seeds of definitional discord may have been sown into Gibson’s original conceptualization, in which he advanced “two, apparently irreconcilable positions,”50 asserting that affordances are intrinsic to the physical properties of an object and at the same time exist only in relation to a subject. Affordances were thus originally conceived as both objective and relational. Movement of the concept from ecological psychology and its reformulation at the hands of Donald Norman exacerbated conceptual uncertainty. Indeed, reviews of the literature on affordance show divergence between definitions derived from Gibson, definitions derived from Norman, and most troubling, use of the term as a central analytic device with no definition at all. Such definitional confusion has become so problematic and widespread that Norman himself has suggested replacing the concept altogether and using “signifier” instead.51
A second critique of affordance is its binary formulation in which objects either do afford or do not afford. Despite early works that emphasize the operation of affordances in “degrees,” such as Warren’s well-known and often cited stair example, practical applications of affordance analyses often depict affordances as either entirely present or entirely absent.52 Binary depictions not only undermine the concept’s analytic integrity but also weaken its capacity as a design tool. Indeed, to capture and evaluate the nuanced interplay between designed objects and user-subjects requires vocabulary that describes affordances that exist between optimal and critical points.53
A third critique of affordance is the continued struggle to account for diverse subjects and contexts. Affordance analyses too often describe artifacts as though they exist in a static and monolithic world. This is a somewhat ironic problem, in that affordance was originally formulated to capture a dynamic object-subject relation. That objects afford in relation to a subject integrates a notion of variability across persons and contexts. Yet in practice, analysts evaluate objects as though their features are inert.54 Such rigid analyses deflate a key strength of the affordance concept by undoing its capacity to capture dynamism between subjects and objects within complex and changing circumstances.
From its origins in ecological psychology, affordance has spanned disciplines and animated robust debate and critique. It was first formulated as an antirepresentational theory of direct perception that contested dominant assumptions about the relationship between organisms and environments. As it moved to design studies, the concept tasked the designer with the responsibilities of the psychologist and placed deep emphasis on guiding user perceptions. Subsequent advances have worked to add precision to the concept and find balance between materiality and subjectivity. Even with these theoretical advances, the term remains plagued by critique, with central intellectual figures suggesting that we do away with the concept altogether. Yet affordance maintains a strong presence across literatures and shows no signs of waning. It is thus advisable that we attend to affordances in a thoughtful manner rather than tossing up our hands and letting the concept take on a life of its own.
Affordance has been subject to critique over conceptual clarity, binary formulation, and static depictions of persons and contexts. Although each of these issues has received significant attention, there is yet to be a systematic framework that addresses them together in a readily applicable way. A key reason for this is that theories of affordance have remained conceptually siloed within specific fields and articulated through discipline-specific jargon. Even as theoretical advances continue, these advances often remain inaccessible outside of niche academic circles. What is needed is a simple and systematic framework of affordance, articulated with vocabulary that cuts across disciplinary boundaries. Building such a framework begins by taking note of the most useful developments within the affordance literature.
Of the three main critiques, conceptualization has been the most effectively addressed and theorists have done so in ways that correct for binary and static applications. Conceptual advances formulate affordances as continuous (rather than binary) and dynamic (rather than static). The work of Peter Nagy and Gina Neff55 and Sandra K. Evans and colleagues56 stand out in this regard. Rooted in communication studies, the conceptual clarifications offered in these works can be applied across fields. Nagy and Neff make the notable contribution of accounting for “webs of relations” between artifacts, users, designers, and contexts in their introduction of imagined affordance. Imagined affordance is an interplay of materiality, intentionality, and serendipity as designers build objects that then take shape through diverse users and changing circumstances. Similar work has emerged in engineering, with scholars articulating affordance relationships between artifacts and each other as artifact-artifact affordances (AAAs), between artifacts and users as artifact-user affordances (AUAs), and artifacts in environments as artifact-environment affordances (AEAs).57 Adding further precision, Evans and colleagues articulate an affordance as that which mediates between features and outcomes. This formulation attends to materiality (features) while recognizing the myriad ways in which materiality can manifest through socially situated subjects, resulting in a range of undetermined outcomes. Thus, affordances are potentialities that operate in degrees through interactions with diverse subjects and circumstances.
Building on these recent advances, the mechanisms and conditions framework provides a common language, untied from disciplinary jargon, that recognizes affordances as both gradated and contextually situated. First introduced as a simple tool that cuts across disciplines to enable dynamic sociotechnical analyses,58 the framework is already being put to use across diverse fields. Scholars have employed the framework to understand complex object-subject relations, account for diverse user practices, and address structural power relations.59 It has even extended out from technology studies to serve as a framework for broader patterns of power-infused interactions.60 I further articulate the mechanisms and conditions framework in the remaining pages of this book, constructing a foundation for affordance analyses moving forward.