It seems that making accessible (and, in this respect, making pub-lic) cannot be equated with the erasing of boundaries. In fact, the opposite seems more likely: The access to space has to be subdi-vided (in time or space) to accommodate different uses and to make room for as many different categories of users as possible.
However, the opposite situation is also true; an architecture with highly specified and restrictive design (figuration) may support territorial fixation and homogenisation, effectively counteracting multiple uses and hence the opportunity for complexity (Kärrholm 2004:278-279). The notion of ter-ritorial complexity will be used to analyse and describe the multifaceted relations between material aspects of architecture and the nature of public life at the sites studied in this thesis.
to an actor by objects in the environment, or as a relational property defined by the association between an actor and the world. The term affordance was derived from the concepts valence, invitation and demand, originating in Kurt Koffka’s Gestalt Psychology (1935). The terms invitation character (J.F.
Brown 1929, in Gibson 1979:138) and valence (D.K. Adams 1931, in Gib-son 1979) are both translations of Kurt Lewin’s term Aufforderungscharak-ter. Kurt Lewin’s description of the term Aufforderungscharakter (English:
demand character, invitation character or valence) implies that affordance appears in the object when we need it – a postbox attains its meaning, or functional utility, when we are to post a letter. Koffka also asserted that this demand character depended on the perceivers’ need; i.e. the value of an ob-ject changes as the perceiver’s need changes (Gibson 1979:138). The phe-nomenon of valence was furthermore intended to be phenomenal and not tied directly to material objects. Gibson built his affordance concept partly on this, but with the crucial difference that his concept does not change with the need of the perceiver (Gibson 1979:138-139).
Gibson (1979:139) posits that the postbox constitutes a phenomenon and an artefact that is present, as an ‘invitation’, in the minds of nearby citizens even when they have no letters to post, as ‘part of the environment’.
In Gibson’s definition, affordances exist independently of individual percep-tion, and they are also independent of the situational needs of the perceiving actor. The following illustration to accompany Gibson’s postbox example aims to explain the relevance of affordance as part of an ontological perspec-tive on how to perceive urban artefacts regarding their potential role as me-diators of socio-material exchanges. In the postal service system (network), the pillar box has an obvious (phenomenal and physical) affordance to hold letters for later pick-up and distribution, but this affordance holds no mean-ing for the perceiver usmean-ing it as a table for a takeaway coffee or merely an artefact to lean on. It then forms part of other networks, exposing addi-tional (hidden) affordances other than those in the postal service network.
Although we have the capacity to be aware of these different affordances, it makes little sense to argue that they exist without being realised. What makes sense is that affordances are tied to actors-in-relation; i.e. expected as well as unexpected affordances appear as effects of situated relations.8
8 Jakob von Uexküll (1980 ) discussed the affordance concept as ‘Ton’ (in English: tone) or ‘funktionale Tönung’ (in English: functional tinting or colouring), suggesting that affordances are not inherent to an object (which Gibson argues).
Instead he proposes a fully relational view, arguing that use is what gives meaning to the world (Ingold 2011:79). Accordingly, Uexküll further argues that an object’s affordances (‘tone’) appear in relation to the perceiver for whom it holds meaning.
Affordances appear in relation to the actor’s activities. Whilst Gibson argues that a stone has the affordance to be thrown, Uexküll asserts that this affordance arises only when an actor actually throws it.
My understanding of the concept is related to an empirical action- or use perspective. From a planning perspective, however, the primary intended af-fordance of a pillar box is relevant even when it is not in use. But the same is true of all of its other potential affordances. In this respect, all latent material affordances are significant – otherwise, planning and urban design would be pointless. In an empirically examined situation, affordances are only inter-esting as performed actions, e.g. when they are realised by interactions.
While applying affordance within an ANT approach, the question of how affordances are expressed is not a matter concerning just the artefact and the perceiver; rather, it is a network-matter: affordances appear and are realised as a result of complex relations between artefacts and humans, culture, conventions, perceptive abilities, etc. When studying social life in public space this is very evident. From an ANT perspective, the Gibsonian notion of affordance as independent of situated actions and related actors’
perceptions is questionable. No action can occur unless related actors’ affor-dances are realised in interactions. In this respect, affordance can be related to agency, since agency has to be exercised to reveal affordance. Accordingly, I posit that affordances are not intrinsic to objects per se; instead, they are subordinate to networks of related actors exercising agency.
Aligning myself with an ANT approach, I would further claim that the possible uses or relations of a space or an artefact can never be exhausted;
thus spaces and artefacts are better understood as having the capacity for in-finite affordances (although not any affordances) than having a limited set of properties. This take on affordance theory avoids an instrumental and causal perspective on how various artefacts (with predefined and fixed properties) affect each other’s use potentials.
An affordance approach can be of use in the analysis of urban life as well as in the design of urban space. Affordance theory suggests that artefacts, and the spaces of which they form a part, do not have a limited and fixed set of functions, meanings and properties. Spaces, as well as artefacts, can produce different effects and meanings because of how they interact with and relate to humans, as well as to other spaces and artefacts. The affordance perspec-tive obviously challenges a traditional view on artefacts and spaces as having absolute and definable properties. From an ANT perspective, affordance is central to the initial associations between networked actors in a cluster, but also in an intentional sense – what are the reasons for the cluster to assem-ble? A cluster has affordances that exceed the affordances of its individual parts, since affordances will change with regard to the nature of associations between entangled actors. Individual affordances can also be completely su-pressed by the cluster’s objectives. Accordingly, there is no causal relationship
between individual actors’ affordances and the affordances of the clustered body.
Affordance is a useful concept in the investigation of actions and events in urban public space. Clusters of humans and nonhumans develop affor-dances that fill gaps, not in relation to a given context but in relation to the affordances of singular objects, humans and nonhuman features. When a cluster unfolds, it has usually been initiated by someone’s actions, driven by intentions or needs, but clusters also emerge due to immanent material affordances – meaning that nonhuman actors can be critical to the forma-tion of specific clusters through strong affordances; for example a sunny, south-facing wall can become a place for rest and sun-bathing; a smooth ground surface attracts skaters; the elaborate façades of Cambridge’s Goth-ic buildings become sites for ‘night climbers’ (Whipplesnaith 2007 ;
Nilsson 2010:185-186); a particularly busy street corner is a popular site for beggars or for charity organisations collecting money. Material, spatial or social particularities allow certain activities to evolve and take place. When an activity has emerged and a cluster is assembled new affordances appear that can induce activities and events not inherent to the separate affordances connected to the individual actors entering the cluster.
In this thesis, I use affordance as an analytical tool to investigate artefacts, nested artefacts and spaces as networks of human and nonhumans to under-stand which different actors are significant for certain actions or sequences of actions, and in what way, Through this analysis, one can distinguish particu-lar material actors that are important for specific actions, events or activities.
I would also suggest that affordance could be exercised in two ways, passive and active: affordance as an invitation, a potential offering – meaning a pas-sive suggestion – and as an encouraging or urging (active) action potential.
The principle modernistic phrase “Form follows function” and its counter-variation “Function follows form” are explicitly and implicitly rooted in an essentialist tradition, and the connotations are noticeably de-terministic. An affordance approach allows for a relational and less instru-mental understanding of how actions, changes, opportunities, events, etc.
are produced or made possible. When studying an urban public situation, the modernist approach easily restrains the possibilities to a set of precon-ceived ideas and expectations, derived from the properties of the materiali-ties and non-materialimateriali-ties available at the site, obscuring unexpected effects and surprises of what new, unknown, constellations might bring about.
The sense of illusory control is evident in this approach and prompts a deceptive sense of being able to foresee events, actions and consequenc-es of complex associations of known and unknown (f)actors. Using the affordance perspective opens up for infinite possibilities, emerging from
swarms of relationships, articulations and associations between humans and nonhumans. Although he is using a more modernistic vocabulary (Forty 2000), Herman Hertzberger (1991:150) touches on aspects of af-fordance when he comments on the reciprocity between humans and the built environment. For instance, Hertzberger argues that the central issue
“is the interaction between form and users, what they do to each other, and how they appropriate each other” and continuously making the social and material relation even more explicit, in a context of practice, using the term form instead of material and competence as alternative to affordance:
“The accommodating capacity of the form, shall we say its ‘competence’, which allows it to be filled with associations and thus brings about a mu-tual dependence with the users” (Hertzberger 1991:150).
Nested and Sequential Affordances
Affordances are sometimes perceived and mutually related in intricate ways. William Gaver (1991:82) has described two ways that affordances might be arranged in relation to an actor and to each other – sequential and nested. He defines sequential affordances as when “acting on a perceptible affordance leads to information indicating new affordances”; i.e. affor-dances that are revealed through entanglement over time. Gaver describes nested affordances as “affordances that are grouped in space” (1991:82).
Nested affordances imply that a particular affordance (or action) can only be revealed through the realisation of several affordances combined.
Urban public spaces usually hold a great many affordances, some of them inherently integrated and some connected to each other by certain users or by means of special situations. Most affordances, I would claim, are sequential and nested, and thus not immediately observable. To reveal affordance capacities of a particular space, one has to enter the space with some intention, hidden or apparent – for example, bringing a personal artefact that might trigger agency in the environment and start a chain of veiled nested affordances, because, as Gaver states, “[a]ffordances are not passively perceived, but explored” (1991:82). Exploration of afforded actions leads to information about what one can do in a particular public domain and how. The learned experiences can be transferred to and test-ed at other sites, and the conditions can be investigattest-ed to see if they are similar or different. Artefacts and spaces may have different affordances in diverse networks or settings; to determine this, the situated conditions must be tested.
Gaver suggests that culture, experience, intentions and social setting affect the affordances that are revealed by an individual perceiver (Gaver 1991:81). This rather obvious remark can have quite serious consequences
for people moving between different urban settings. Since affordances are relational effects, affordances that are obvious to some may be concealed or even disguised for others. Arriving from a different urban culture can affect one’s ability to make use of obtainable affordances and thus complicate the accessibility of certain publics or collectives. As I will show below, some-times certain artefacts are requested to realise affordances that are nested in a space – a kind of sequential affordances that can be revealed through par-ticular materialities. For example, by bringing toys to a sandpit, children investigate, reveal and realise different affordances related to sand; people with skateboards explore topographical affordances connected to various urban materialities, through their wheeled artefacts.