Presence and the Content of Virtual Environments
Virtual Reality Applications Research Group
University of Teesside
This paper considers the role of the content of Virtual Environments (VEs)
in generating presence. This is achieved by actively considering the way
content affects perception. The thoughts on presence presented here arise
not from from direct research into presence itself but from the practical
experiences gained in building desktop VEs and then reflecting on the way
people did or did not respond to particular content. Of particular importance
was a virtual tourist site built for the Saltburn Improvement Company on
the North East of England and which has served as a test bed for the ideas
put forward here .
2 The Nature of Presence
It would seem indisputable that human beings have the ability for not
being mentally present in an environment in which they are observably physically
present. This sense of presence, the feeling of being there,
is at the heart of our experience of virtual reality.
A sense of presence is not restricted to experiencing VEs but is also
associated with story telling and reading, and of course film and television.
Rather, presence in VEs is just perhaps the most recent example of the
degree to which humans are naturally inclined to be taken out of themselves,
enjoy immersing themselves in environments artificially created through
communications media of all sorts. An intriguing thought experiment
using an extreme example of this can be found in Zhai . The difference
is that VEs go further than any other communications media in generating
artificial stimuli for the perceptual systems to interpret rather than
delegating the interpretation and creation to the mind itself as is the
case with novels and story telling.
Hence Lombard and Ditton's characterisation of presence as the perceptual
illusion of non mediation . This characterises presence as
the state of mind of a visitor to a VE as not noticing or choosing
not to notice that that which they are experiencing and interacting with
is artificially generated. They document the evaluation of the embodying
interface of a VE in terms of presence seen largely as the degree of fidelity
of sensory immersion. Much of the research to date into presence is particularly
concerned with the embodying interface as well as researches into the mental
state of people who are present in VEs.
However, as presence is a mental state it is therefore a direct
result of perception rather than sensation. In other words, the mental
constructions that people build from stimuli are more important than the
stimuli themselves. It is the patterns that we, as VE constructors, build
into the various cues that make up the available sensory bandwidth for
a given VE that help or hinder perception and thus presence. These patterns
are the result of what is built into the VE and the way the user behaves
in response to them The fidelity of the sensory input is obviously a contributing
factor but by no means the most important. In the context of the working
VE builder, being able to identify and make effective use of the causes
of presence is more important than the nature of presence itself. This
means that it is the effective consideration of the perceptual consequences
of what we build into VEs that will give rise to the sense of presence
that we are looking for. In this sense it is the content of VEs that has
the greatest effect on the generation of presence.
Not all researchers have seen presence itself as the main focus of interest.
Ellis  states that the design of VEs should focus on the efficient
communication of causal interaction and that presence is an epiphenomenon
of secondary importance for design. This view would also seem to be
asserting that effective content design is of primary importance.
Before proceeding to address this question we should note that what
we have been referring to here is what Stone  refers to as a classical
view of presence, i.e.. the unique persona within the physical body transported
to a mediated world, rather than the transformation of persona or instances
of multiple persona within the same physical body. This is rarely dealt
with in the academic discussions recently published but the transformation
of self is surely a major contributing factor to presence in many VEs particularly
games oriented or those such as the Hubble Space Telescope VTE where the
ground team were effectively taking on the roles of astronauts to better
help them during EVAs .
3 Content for Virtual Environments
It would seem that there are a number of disciplines from which we could
gain pointers to help us understand the nature of the content of VEs. Recent
research indicates that film and architecture, have much to teach us in
this respect. The nature of the content of films has been often been the
object of study of film theory over the course of the century and such
concepts as montage and mise en scene would seem to have
much to teach us . It would seem that space syntax has much to
teach us about the generic function of space prior to perception and that
the axis is, perhaps the conceptual equivalent of mise en scene . The
axis is fundamental because the experience of architecture is the experience
of movement - Hillier referring to Le Corbusier .
A tentative characterisation of the content of a VE is as a set of perceptual
opportunities allowing the visitor to accumulate over time a set of experiences
which maintain a sense of purposive presence. Content thus seeks to:
In the next section we will attempt to attempt to identify
some design principles for VEs to realise the above.
establishment and maintain a sense of purpose which is reinforced by some
or all of the accumulating experiences
generate a sense of causal interaction 
maintain general belief in the VE irrespective of purpose.
4 Perceptual Modelling
Establishing the psychological qualities of a VE that seek to gain and
hold the visitors attention through the human senses and perceptual system.
The mutually supportive effects of:
The perceptual is about details which arise naturally from the spatial
world and involve the visitor both consciously and unconsciously. The latter
is very desirable because there is something very fundamental about unconscious
involvement - accepting a place or activity without thought. Animations
are very good for attracting attention, particularly in the distance or
at the periphery of vision because the detection of movement is one of
our most basic perceptual mechanism.
Movement - both vection and autonomous.
Interaction - all the time we are doing something in a VE we are less likely
to be criticising the decor.
Sound - to complement visual and interactive stimuli.
Other - haptics etc. if the system allows.
These details break down into two mutually sustaining forms:
Mundane details that are somehow highly predictable - their attraction
is their predictability. This is also about small things. Navigation cues,
indicators of scale, and distance cues. The latter because distance cues,
as people would normally recognise them, are largely absent in VEs. This
is also true for cues for the scale of objects and one's own avatar. Such
perceptual cues arise directly from the architecture of the space and are
concerned with the logic of the environment unconsciously accepted .
Examples might be
Lampposts, railings, and street and other furniture in general
A very important role of cues is to make VEs more dynamic and cluttered
- we are used to the real world being like this so it helps if virtual
ones are as well whatever the specific purpose. The following quote gives
an insight from photography into the nature of cues in VEs:
Being able to open a door by turing a door handle.
The sound of the hinges creaking.
A working calculator on the virtual office desk.
The sound of the keys being tapped on the calculator.
Hence the detail that interests me is not, or at least is not strictly,
intentional, and probably must not be so, it occurs in the field of the
photographed thing like a supplement that is at once inevitable and delightful.
These are "appropriately designed infidelities"  which
can be used for emphasis in virtual worlds and also relate to conscious
learning. In other words, non mundane details that are not predictable
but they do arise however surprisingly from the logic of the space consciously
Video clips running in picture frames.
CDs that play themselves and have control keys in the case.
Virtual user manuals that pop up to help you use the mundane objects
Visual and auditory feedback and help in VTEs.
Sounds and soundscapes devoid of causal phenomena
4.3 Cues and Surprises Working Together
Fidelity in VEs works much in the way jokes do.
My dog has no nose!
The first two lines are unremarkable and mundane, cues. The third line
comes as a surprise but is plausible from the logic of the first two statements.
Jokes seem to be all much like this - you set up an imagined and consistent,
however fantastical, world and then give it a bisaar, implausible twist
which must somehow be derivable from the former. Cues and surprises in
VEs work together, supporting each other and thus the virtuallity they
inhabit by seeking to both establish fidelity and catch and retain the
attention of the visitor and thus maintain presence.
How does he smell?
These ideas arose out of the practical activity of VE building and are
the result of trial and error, playing with prototypes and so. It would
seem that as the embodying interfaces of virtual reality become established
and the sensory bandwidth more widely covered we will need to switch our
attention to the nature and content of virtual reality if we are to build
effective VEs. If presence is indeed primarily the perceptual result of
appropriate content then a deeper understanding of the the way in which
the human perceptual systems respond to VE generated content will be a
major research area for the near future. It would also seem of great benefit
to investigate the theoretical underpinnings of other disciplines, such
as film and architecture, to support this activity.
 Clive Fencott, "Using a VRML World to Investigate content and Presence",
 Philip Zhai, "Get Real: A Philosophical Adventure in Virtual Reality",
Rowman & Littlefield, 1998.
 Mathew Lombard and Teresa Ditton, "At the Heart of It All: The
Concept of Telepresence", in Journal of Computer Mediated Communication,
Volume 3, No 2, September 1997 http://jcmc.huji.ac.il/vol3/issue2/
 Stephen R. Ellis, "Presence of Mind: A Reaction to Thomas Sheridan's
"Further Musings on the Psychphysics of Presence"", in Presence, Volume
5, No. 2, Spring 1996.
 Allucquere Rosanne Stone, "The War of Desire and Technology at
the Close of the Mechanical Age", The MIT Press, 1996.
 R. Bowen Loftin and Patrick J. Kenney, "The Use of Virtual Environments
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 Andrew J. Dudley, "The Major Film Theories: An Introduction", Oxford
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 Bill Hillier, "Space is the Machine", Cambridge University Press,
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