G e n e r a l n o t e
Toward an Ontology of the Interface
Identifying the Interface as a Mediation Entity
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The interface is more than an assemblage of processes and effects; it is
more than a pure relational instance. The interface can be identified as
an entity in itself and in relation to other entities. In questo articolo, the author
presents an ontological work on the interface, defining what it is and
how it exists, and discussing its relation to other entities. The interface
is defined both abstractly as a mediation complex—by identifying
characteristics present in its multiple instantiations—and in relation to
other entities—by observing the case of the human-computer interface.
The interface is a system or device through which nonrelated
entities can interact [1]. From this definition, I conclude that
the interface must have some characteristics that are com-
mon to each of the entities it puts in connection, since it
must communicate with each of them. Ancora, the interface is
more than simply a relational space that inherits properties
from the systems it connects: It is itself an entity with its own
features that emerge from the interaction occurring through
and by means of itself. Finalmente, the interface has features of
its own apart from the interaction it facilitates—features that
produce or shape experience [2]. On another level, the defini-
tion of the interface also encompasses the ubiquity and vari-
ability of the interface: It is present between diverse entities,
so it can take on virtually any form or function—a graphical
user interface or a public transportation hub, for instance.
The main objective of this article is to define what the in-
terface is and how it relates to other entities, thus advancing
the construction of its ontology. The first section below de-
fines the interface and its mode of existence abstractly—i.e.
valid for any of the interface’s multiple instances. The second
section discusses how the interface relates to other entities by
concentrating on a particular instance: the human-computer
interface.
Cristina Sá (educator), Universidade Católica Portuguesa, CITAR—Centro de
Investigação em Ciência e Tecnologia das Artes, Escola das Artes, Rua Diogo
Botelho, 1327, 4169-005 Porto, Portugal. E-mail: csa@porto.ucp.pt.
ORCID: 0000-0003-3143-420X.
See www.mitpressjournals.org/toc/leon/52/5 for supplemental files associated
with this issue.
Interface is defined within the theoretical framework
of mediation and experience [3]. According to Kittler [4],
from Aristotle onward ontological studies have dealt only
with things—their matter and form—and not with the rela-
tions between things in time and space, therefore leaving
mediating entities out of such studies. Because I study the
interface as a mediating entity, we must begin our discussion
by defining the interface and describing its relationships in
space-time (and matter, which can no longer be separated
from space and time).
WhAT IS An InTeRfACe?
Definitions of interface often consider its space and actions
(time), thus contemplating its relational and emergent char-
acteristics. Most definitions of interface, Tuttavia, ignore its
substance (matter), thereby ignoring certain characteristics
[5]. In this section, I study the interface as a complex [6],
acknowledging its space-time-matter.
Interface and Space: Between, Discontinuous, Adjacent
Space has been defined in distinct ways throughout history.
Some of these definitions have become important conceptual
tools [7]: Plato’s work on space provides aids for defining the
interface’s “in-between” mode of existence, quantum physics
demonstrates the pervasiveness and fundamental role of the
interface in sustaining the discontinuous complex of reality
and Foucault’s experiential work on space exposes adjacency
as fundamental for relational occurrences.
Spazio, for Plato, is in between being and becoming [8]. It
operates as a receptacle for things and beings. The interface
also stands between ontologically different realities, distin-
guishable by their conception, genesis and apprehensibility.
It is a receptacle for beings: beings in formation and trans-
formation, passing from one world to another.
To apprehend Plato’s space, one needs “a kind of spurious
reason,” which is also the case for the interface, as is discussed
in the following section; Plato describes space as a portal
“which we behold as in a dream” [9]. The interface is also a
provocative agent, a space that invites us to move to another
©2017 ISAST. Published under a Creative Commons Attribution 4.0
Internazionale (CC BY 4.0) licenza.
https://doi.org/10.1162/leon_a_01450
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reality. Inoltre, dreams as emotional landscapes put the
interface within the realm of fantasy and desire. By going
beyond the fulfillment of a need, the concept of interface is
connected to the Lacanian concept of object petit a: facili-
tating and promoting access to another reality by means of
continuous satisfaction [10]. In short, the interface is a space
of perception, action and desire—a space of agency in Hook-
way’s terms: “the will and means to action” [11].
Since Einstein, understanding space-time implies con-
sidering masses, particles and their behavior through their
relationship with light. Quantum theory [12] asserts that all
entities, although apparently continuous, are really made of
particles. Reality is a noncontinuous heterogeneous woven
fabric, but with such a fine texture that it suggests continuity
to our perception. Reality depends on the interactions among
its elements to maintain its unity—to exist. The idea of an
interface traverses this discontinuous continuum of reality,
since its presence is fundamental as an element of dynamic
liaison: granting the existence, multiplicity and mutability of
the fabric of reality.
Foucault [13] proposes another vision of space, stating that
our experience of the world is network-like: The experiential
relationship of space-time is one of connection and weaving.
The position of experience in space and its distribution in
time do not obey conventional geography or the successive
linearity of history. Events are represented by neighborhood
and connection more than by position or date. Adjacency
becomes the basic condition for a relational occurrence me-
diated by an interface: “Inter- encompasses relations that may
occur between, among, or amid elements insofar as they are
given as bounded within the space of their relating, or of the
events insofar as they are bounded in time” [14].
Interface and Time: Speed, Iteration, Harmonization
Speed is a relational concept, since it considers the distance
(spazio) covered in time by a mass. Paul Virilio studies speed
through telepresence and uses light exposure as an alterna-
tive measure of time [15]. Time becomes chronoscopic in-
stead of chronologic. Like objects in a photograph, an event
in time may be underexposed, exposed or overexposed
[16]. The time of the interface is also one of exposure: UN
thing or event only exists for the other system if “exposed”
in the interface. If the thing or event is underexposed, IL
other system cannot acknowledge it; if, on the contrary, Esso
is overexposed, then it loses its novelty and interest (it is
saturated).
Another aspect to consider is the iterative nature of inter-
face time. According to Pierre Robert [17], the interface is
built around two rhetorical axes: The first is developed at the
moment of its conceptualization; the other unfolds through
interaction. The interface is reconceived by each action, In
an iterative process, not in a cyclic one.
Finalmente, the time of the interface depends on rhythmic
harmonization, which is related to cybernetics [18] through
feedback. The entities that interact might operate in differ-
ent time units or in different rhythms; it is the role of the
interface to make them compatible.
fig. 1. Char Davies, Osmose, immersive virtual environment,
1995. Immersant wearing a stereoscopic head-mounted display and
breathing/balance interface vest during a live performance of Osmose.
(© Char Davies. Photo: Jacques Dufreine.)
Interface and Matter: Transmission, Plasticity
The interface has a matter whose presence depends on action:
It becomes in interaction: it is formed while transmitting.
It becomes “visible” when transmission occurs; its matter is
concretized at each moment of interaction. Therefore, inter-
face matter is dynamic, both in composition and in shape,
making it comparable to plastic material [19]:
• Malleable: The interface receives its form from the
gap between entities; it is molded dynamically by
them and molds them in turn [20].
• Superficial/coating [21]: The interface sticks to enti-
ties, covering them, laminating them, sometimes
becoming indistinguishable from them. This coating
makes it possible for entities to see each other, albeit
through a mediating layer.
• Artificial [22]: There is always something artificial
about the interface: precisely that which is natural to
the other entity.
• Synthetic [23]: The interface synthesizes something
new every time it promotes the encounter between
two entities: the Hegelian attribute of plasticity.
Composite materials [24] are made from two or more
constituent materials that, when combined, produce a
480 Sá, Toward an Ontology of the Interface
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material with characteristics different from the individual
components. The interface is made of different original ma-
terials combined, not fused, into a heterogeneous complex.
This heterogeneity does not compromise its unity; on the
contrary, heterogeneity is the very foundation of the inter-
face [25].
Simultaneous creation [26] occurs in composite plastics
because they gain form and define their composition at the
same moment—in action—just like the interface.
Char Davies’s Osmose (Color Plate C, Fig. 1) exemplifies
what is meant by the plasticity of the interface [27].
hOW DOeS The InTeRfACe
RelATe TO OTheR enTITIeS?
In this section, I analyze the relational mode of the interface
with its bounding entities. We leave the abstract sphere and
address the instance of the human-computer interface and
how it relates to its bounding entities: humans and computers.
I focus particularly on how humans perceive the interface,
asking two questions: (1) How does human perception relate
to the passage between actual and virtual? (2) How does hu-
man perception affect the meaning of transparency in con-
temporary digital culture? Both these questions are analyzed
in the light of aesthetic computing—“the application of art
practice and theory to computing” [28], while implications
for interface design are noted.
Articulating the Intelligible with the Sensible
While Actualizing the Virtual
Human-computer interfaces corroborate two observations
made by Paul Fishwick in justifying a move toward aesthetic
computing:
(1) aesthetics in computing are broader than the purely
cognitive dimension; E (2) the art-science confluence
embedded within the discipline of interaction design is
broader than the primary “desktop” interface [29].
1. To understand the interface itself, we need to use
hybrid reasoning. In the case of human-computer
interfaces, that reasoning must be simultaneously
mathematical and sensible, for those are the modes
of “perceiving” on both ends. Alain Renaud considers
this to be the central operation of the interface:
a process of intellectualizing the sensible and
embodying the intelligent by actualizing the virtual
[30]. Human-computer interfaces congregate cogni-
tive and material aesthetics by articulating the intel-
ligible with the sensible and actualizing the virtual
all in the same movement. In human-computer inter-
faces, the cognitive dimension is no longer pure at
the interface layer: Cognitive behavior is simultane-
ously sensible and intellectual, for such is the trans-
lation and transmission (the operation) the interface
guarantees. This coordination is also present in the
actual/virtual translation if we consider the quan-
tum physics principle that there are no measurable
continuities in physics. There is no abrupt passage
between actual and virtual—there is no moment or
point of discontinuity in the interface where magic
happens and the analogic (continuous) becomes digi-
tal (discontinuous). Both realities are discontinuous
but at different levels. Aesthetics in computing are
hybrid (material/virtual and cognitive/sensible) at
the interface layer.
2. The art-science confluence and the diverse ways
in which that confluence is revealed on human-
computer interfaces can serve as models for other
dimensions of interaction design, proving that that
confluence is broadly embedded in the discipline of
interaction design. Inoltre, since Foucault, rete
vocabulary has defined experience. A relational mode
of experience pervades our digital culture. This mode
is important in terms of user experience and conse-
quently in terms of the possibilities for experience
progetto. Again, interface concept and design can be
the model to replicate when considering experience
progetto.
Transappearance through
Biodigital Rhythmic Harmonization
The chronoscopic measure of time reinforces the idea of in-
terface as a receptacle of objects, not only in space (as in
Plato’s formulation) but also in time. Interface is the space-
time structure that supports Virilio’s real-time perspective
[31]. In terms of human-computer interfaces, this means it
is the role of the interface to control exposure, becoming a
window in time—a special window, since its matter is plastic.
The plasticity of the interface, combined with the fact that the
interface gains matter intermittently through transmission,
guarantees its transapparent mode of existing (transparent
and opaque, commutatively).
Interfaces are transparent because there is a need to see
through them, and they are apparent because there is a
need to operate them and identify with them (as mirror).
If well realized, both these characteristics are experienced
simultaneously. Being transapparent is being beyond appar-
ent—being apparent yet traversable, like Alice’s mirror. Quello
is how transparency is experienced in digital culture: seeing
through and being visible in apparent simultaneity. Rhythm
becomes fundamental to achieving transappearance. In
human-computer interfaces the rhythmic harmonization is
biodigital [32].
Transappearance proves that time and matter are key to
developing a well-balanced interface space in terms of trans-
parency/opacity in perfect commuting rhythm. There should
be equal efforts made to conceive spatially compelling in-
terfaces and to control the exposure time of an interface’s
elements. Interaction design addresses the temporal aspect
of digital artifacts [33]; pliability is an aesthetic quality in the
use of these artifacts. The interface has the quality of pliability
through its plasticity. The matter of the interface is the op-
erational means for conceiving an effective spatial-temporal
interface.
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Sá, Toward an Ontology of the Interface 481
COnCluSIOnS AnD fuTuRe WORk
An ontological approach to the interface implies defining what
an interface is and how it exists. The interface’s inscription
in space-time-matter provides this definition: The interface is
a complex; it is an intricate fabric of qualities and processes
that enables the interaction between two or more systems.
The interface exists in the discontinuities of reality. Its space
is one of passage, its time is one of exposure and its matter is
dynamically heterogeneous, in both shape and composition.
Another ontological aspect to consider is how the inter-
face relates to other entities. The operations performed on
the interface and how interaction occurs through it evince
another element fundamental to understanding the interface:
mediation. The interface is a mediation complex dynamically
and iteratively constituting itself both as a plastic window and
as a traversable mirror.
To complete this ontological work, our next steps will be
(1) to study other relational aspects of the interface, approach-
ing key concepts of digital culture such as subjectivity, Immagine
and art, E (2) to create a classification system for inter-
faces—a taxonomy, preferably—that will distinguish intrin-
sic from contextual characteristics of the interface.
Ringraziamenti
I am thankful to the reviewers: Their extremely constructive critique
added new dimensions to this work. Sponsored by National Funds
through FTC—Foundation for Science and Technology, under the proj-
ect UID/EAT/00622/2019.
References and Notes
1 In the online supplemental file, I analyze this definition and the char-
acteristics of the interface through an example.
2 In Hookway’s terms, this study of the interface follows both the “be-
tween faces” and the “faces between” approach. See Branden Hook-
modo, Interface (Cambridge, MA: CON Premere, 2014) pag. 9–11.
3 The online supplemental file contains a detailed justification for
choosing this framework.
4 Friedrich Kittler, “Towards an Ontology of Media,” Theory, Culture
impossible to read. The OSTF discusses the implications of chro-
noscopic time.
17 Pierre Robert, “L’interface: Le bien de la communication,” in Louise
Poissant, ed., Interfaces et Sensorialité: Esthétique des Arts Media-
tiques (Saint-Foy Québec: Presses de l’Université du Québec, 2003)
pag. 115–122, P. 116.
18 Norbert Wiener, Cybernetics; O, Control and Communication in the
Animal and the Machine, 2nd Ed. (New York: CON Premere, 1961) pag.
35–38.
19 I follow Malabou’s multidisciplinary work on the concept of plastic-
ità: Catherine Malabou, ed., Plasticité (Paris: Léo Scheer, 2000).
20 Bernadette Bensaude-Vincent, “La plasticité des materiaux nou-
veaux,” in Malabou [19] pag. 170–185, P. 171.
21 Jeffrey L. Meikle, “De l’immaterialité virtuelle: Plastiques et plasticité
au XXe siècle,” in Malabou [19] pag. 146–169, P. 150.
22 Meikle [21] P. 148.
& Società 26, Nos. 2–3, 23–31 (2009).
23 Catherine Malabou, “Le voeu de plasticité,” in Malabou [19] pag. 6–25,
5 The online supplement contains definitions of interface from differ-
ent authors and fields.
6 “Complex” comprises space-time-matter and therefore respects the
three types of characteristics of the interface: inherited, emergent
and constitutive. The online supplement explains the framework
used to study this complex.
7 The online supplement presents these definitions and concepts of
space in detail.
8 Plato, Timaeus (Project Gutenberg, 2008): www.gutenberg.org
/etext/1572 (avuto accesso 27 Luglio 2016).
9 Plato [8] P. 300.
10 André Nusselder, Interface Fantasy: A Lacanian Cyborg Ontology
(Cambridge, MA: CON Premere, 2009) P. 13.
11 Hookway [2] P. 5. See also Brenda Laurel, The Art of Human-
Computer Interface Design (Boston: Addison-Wesley, 1990) P. xii,
where the example of a doorknob as human/door interface exposes
this agency.
12 David Deutsch, The Fabric of Reality (London: Penguin, 1998) pag.
P. 10.
24 Bensaude-Vincent [20] P. 174.
25 The online supplement contains a discussion on this subject.
26 Bensaude-Vincent [20] P. 173 (“la prise en masse” and “la mise en
forme”).
27 This artwork’s interface is discussed in the online supplement, both
in its concept and regarding its plasticity. See Char Davies, Osmose:
www.immersence.com/osmose (avuto accesso 17 Marzo 2017).
28 Paul Fishwick et al., “Perspectives on Aesthetic Computing,” Leo-
nardo 38, No. 2, 133–141 (2005) P. 133. The online supplement details
the framework.
29 Fishwick et al. [28] P. 134.
30 The online supplement details the author’s idea. Alain Renaud,
“L’interface informationnelle ou le sensible au sens de l’intelligible,"
in Poissant [17] P. 69.
31 Virilio [15] pag. 31–33. The online supplement details the author’s
theory.
32 The online supplement presents examples of this harmonization.
35–36.
33 Fishwick et al. [28] P. 138.
13 Michel Foucault, “Of Other Spaces: Utopias and Heterotopias,” Ar-
chitecture, Mouvement, Continuité 5 (1984) pag. 46–49. Available at:
www.foucault.info/doc/documents/heterotopia/foucault-heteroto
pia-en-html (avuto accesso 27 Luglio 2016).
14 Hookway [2] P. 7.
15 Paul Virilio, Open Sky (reprint ed., London: Verso, 2003) P. 3.
16 Virilio [15] pag. 27–28. An object underexposed to light is not cap-
tured on film; an object overexposed to light becomes saturated and
Manuscript received 29 novembre 2016.
Cristina sá is an assistant professor teaching courses in
media art history, aesthetics of interaction and digital culture.
She has a strong commitment to interdisciplinary work in fields
such as art and technology, influenced by a formative educa-
tion combining engineering, art and communication.
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Color Pl ate C: TOwARd An OnTOLOgy Of ThE inTERfACE:
idEnTifying ThE inTERfACE As A mEdiATiOn EnTiTy
C
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Char Davies, Osmose, immersive virtual environment, 1995;
Tree, digital still image captured during a live performance of Osmose.
(© Char Davies) (See article in this issue by Cristina Sá.)
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