The good, the bad, and the downright misleading: archaeological
adoption of computer visualization
Paul Miller^ and Julian Richards^
Department ofArchaeology, University of York, The King's Manor, York, YOl 2EP, UK.
Email: 'apm9@york.ac.uk, ^jdrl@york.ac.uk
3.1 Introduction
Over the past decade, archaeologists have been quick to
adopt the techniques of computer visualization, often with
eye-catching effect (Reilly 1988, 1992). The images
produced by these techniques serve to enable
archaeologists and public alike to visualize past
monuments, landscapes and excavations, truly bringing
the past to life. Over the years, delegates to CAA
conferences have been awed by the latest piece of solid
modelling, or reduced to avaricious jealousy by the price
tag on the computer producing it.
We suggest, however, that there are dangers, both in the
techniques themselves and in the way they have been
utilised within archaeology; dangers that to a large degree
have gone unrecorded by practitioners and the greater
archaeological community alike.
3.2 Visualization
'•visualization' as used here refers to the computerised
exploration of data which have been converted into
displayable geometric objects. However, it is more than
the application of image processing, solid modelling, or
GIS techniques. Visualization is an interactive process
whereby large and potentially complex data sets may be
displayed on the computer screen and explored to reveal
new insights. It is also a methodology, a way of looking at
and approaching the problems of imparting data to an
audience. As such, computer-based visualization has
tremendous research potential within a discipline such as
archaeology:
• archaeology is a very visual subject. Its data frequently
comprise images - of artefacts or sites; aerial
photographs, geophysical survey plots, satellite
images, or excavation plans
• archaeological data sets can be very large, with a
single survey or excavation producing thousands of
records
• archaeological data can be extremely complex, with
uncharted relationships between a number of variables
However, to date the catalyst for visualization in
archaeology has not been the search for improved
techniques for discovering new knowledge but rather for
improved ways for presenting existing knowledge to the
public.
3.3 Visualization in Archaeology
The general perception of computer visualization in
archaeology is of impressive but expensive computer
reconstructions of some of the major buildings of
antiquity. Indeed, in Britain, visualization projects
originated in the 1980s, starting with Bowyer and
Woodwark's reconstruction of the Temple Precinct from
Roman Bath (Smith 1985; Woodwark 1991), and that of
the Roman legionary bath house at Caerleon in Wales
(Woodwark 1991).
These pioneering projects inspired a succession of
visualization applications elsewhere in the UK, including
the Saxon Minster at Wmchester (Burridge et al. 1989),
the Cistercian foundation at Fumess abbey in Lancashire
(Wood & Chapman 1992), the Roman palace at
Fishboume (Comforth & Davidson 1989), or Kirkstall
abbey (Dew et al. 1990).
Due to the success of the earlier temple project, Bath
City Council commissioned a second model, resulting in a
short video of the civic bath complex (Lavender et al.
1990). The resulting video provided a walk through the
civic bath complex and consisted of hundreds of images,
each of which took many minutes to compute on powerful
workstations. As with other models, the final video was
impressive, but it was impossible to deviate from the route
laid down by the programmers and even the single images
were far from interactive, due to the time required for
computation.
Elsewhere in Europe there were other experiments with
visualization technology including the Stabian baths in
Pompeii (Moscati 1989), the medieval church of St
Giovanni in Sardinia (Soprintendenza Archeologia Per le
Provincie di Sassari e Nuoro 1989), the Athenian
Acropolis (Eiteljorg 1988), or the pyramids at Giza in
Egypt (Labrousse & Comon 1991).
With all of these models, the raison-d'etre was to make
a reconstruction of the site accessible to the general
public. They are generally of buildings which have been
excavated or recorded, but where poor survival makes it
difficult to visualize the appearance of the original
structure without artificial aids of this type. For example,
the Civic baths complex in Bath is one of most visited
tourist attractions in the UK with around one million
visitors each year. The surviving remains, although
impressive, are only a faint echo of the original imposing
structure, and are overshadowed by later structures.
19
PAUL ME-LER AND JULIAN RICHARDS
An important factor is that most of these computerbased
projects are concerned with Classical or
Romanesque architecture. In most cases the architectural
principles are well understood. The building foundations
had been excavated and the above ground appearance was
known, or at least calculable, from surviving buildings.
Therefore in each of these cases the archaeologists had
already formed a fairly clear view of what the building
looked like before they considered developing the
computerised model. Thus there was little extra to be
learnt by constructing the model. This is not to say that
the visualization failed to provide any new insights, but
merely that it was not the primary aim of the project.
The models were developed on equipment that was at
the time state of the art, and using software that was only
available in a limited number of corporate research
centres. In most cases they were the result of sponsorship
by a large commercial organisation, such as IBM, Fiat, or
BNFL who had quite cynically targeted archaeology as a
discipline in which they could gain public relations points
in an area which was politically safe, and at relatively
little cost to them. They were each aware that archaeology
attracts media attention and arouses large-scale
sympathetic public interest, while those working within
the profession would welcome collaboration due to lack of
resources.
Each project was a result of collaboration between
computer scientists and archaeologists, rather than being
archaeologically controlled. In most cases the
visualization software itself was not accessible to the
archaeologists and therefore the computer scientists were
interposed between them and their data. The
archaeologists did not have direct control of the modelling
themselves.
These high-tech reconstruction models are the direct
successors of the water-colour drawings of Alan Sorrell
which still grace many site guide books. The increasing
use of computer-based reconstructions has not been
developing in isolation, and may be seen as a result of
several, related, factors;
• the recent and massive growth of the heritage industry,
and the explosion in museums and heritage centres,
opening it has been estimated in the UK, at the rate of
one per day (Hewison 1987). Besides being under
growing pressure to find new ways of attracting the
public, museums and heritage bodies also have the raw
materials necessary.
• as a result, there is money available for model
development within the 'Heritage Industry'.
• although initially expensive, computer modelling is
now relatively cheap, and when compared with the
cost of employing a draughtsman for several months to
prepare a single drawing, the development of a
reusable computer model may be the cheaper option.
• the increased expectations of a public used to a diet of
high quality multimedia-media presentations, from
school learning software upwards.
However, these models carry a degree of authority
which Sorrell's drawings never had. No clouds or wisps
of smoke hide those areas where interpretation was
difficult; the question marks and qualifications of the
excavation report are reduced to the clinical fixed
measurements of the architectural plan. Furthermore,
computer models carry more authority than paper images;
people expect computers to be right, and the past is
therefore presented as a known - and knowable - reality.
We do not know of any examples where alternative
reconstructions have actually been published and clearly
there is a major danger here. Large audiences are being
exposed to visualizations in circumstances where the
pictures or animations are divorced from the academic
discussion (both technical and theoretical) associated with
their development. Most archaeologists are keen to
emphasise that there are many possible views of the past,
and that we rarely know anything for certain, but these
computer models are constrained by the short-term
attention span the heritage industry assumes museum
visitors to possess, and the small time-slices devoted to
any one model amongst the plethora of images and
displays bombarding the visitor. In presenting a very
visual and solid model of the past there is a danger that
techniques of visualization will be used to present a single
politically correct view of the past, and will deny the
public the right to think for themselves.
This is not a problem that is unique to archaeology.
Under the heading of 'Lies, damned lies and slick
graphics' New Scientist (Kieman 1994) warned that
computer graphics could be tricking the public - and even
the scientists who use them - into believing that
speculations or forecasts were in reality proven fact.
Speakers at the Conference of the American Association
for the Advancement of Science recently noted that in an
image-hungry world, a computer forecast of patterns of air
pollution was more effective in influencing policy makers
and politicians than dry tables of numbers and charts.
Worryingly, there is little, if any, quality control for
computer graphics and they are not subject to the same
intense peer review as scientific papers.
Part of the fault also lies with the visualization tools
themselves. Rarely are they capable of displaying
uncertainty or fuzzy data. One needs to be able to display
levels of probability that a wall stood where it is shown,
and the level of confidence in a computer generated
terrain model.
An application area where these, and other,
considerations are especially pressing at present is the
field of GIS, variously described as 'the greatest thing
since the map' and 'just another bandwagon'.
In archaeology, as elsewhere, the advent of powerful
GIS (Allen et al. 1990) has enabled a revolution in the
ways in which spatial data are visualized and explored.
Allied to this visualization revolution has been the
20
THE GOOD, THE BAD, AND THE DOWNRIGHT MISLEADING
lowering of barriers between archaeologists and their data;
no longer do we need a computer scientist to write our
software, a geographer to analyse our distributions, or a
cartographer to draw our maps. Now we do it ourselves.
This has enabled many archaeologists to explore their
data in ways that were impossible or prohibitively
expensive before, but it has also allowed the possibility of
far lower standards for work of this nature.
A cartographer does far more than draw maps. He has
been trained for many years in the science of cartography,
and has an awareness of how different elements of map
composition go together to make up the whole. In any
map he prepares, all of this knowledge and experience is
brought to bear, adding to the overall quality of the map,
and the accuracy of the information conveyed (Tufte
1990).
By allowing untrained archaeologists loose with a GIS,
they have the tools at hand to produce maps superficially
of the same, if not greater, quality to that produced by the
cartographer, but without the background expertise.
Given such a plethora of tools, it becomes all too easy to
generate pretty but meaningless or even misleading maps.
Even allowing for the problems of map composition
and design, the most able map creator faces many
difficulties in representing multidimensional
archaeological data within the constraints of the two
dimensional display medium. As archaeologists, we face
very different visualization problems to those encountered
by other social scientists as our maps do not merely record
the distribution of occurrences through space, but also
attempt to represent their temporal distribution (Castleford
1992).
Complications begin to arise when data or analysis
move beyond the first two and into the less conceptually
concrete 3rd and 4th dimensions. Whilst we can perceive
these dimensions (up as opposed to down, early rather
than late), representing them within GIS in such a way
that they may be visualized and manipulated is proving a
great challenge. Several ingenious solutions have been
found to the problem, but they tend to rely upon the use of
snapshots, or slices through the dimension under study
(Castleford 1992; Kvamme 1992). This approach enables
basic visualization, but dissociates data from their
fundamental inter-relationships. We become resigned to
viewing only part of the whole, and begin to forget that
our maps are only components of a totality in which past
influences present, and low elevations interact with higher
ones.
In order to truly explore our data, it is necessary to
investigate the means by which true multi-dimensionality
may be built into our visualization systems. For detailed
research, interactive links between data, images and user
are also vital, and more important than the aesthetics of
the image itself.
As mentioned earlier, a major aspect of any
archaeological visualization is to create representations of
archaeological data that may be seen and understood by
other archaeologists and the general public. With this in
mind it is important that we recognise the limitations of
current techniques and find ways to represent the failings
in both our data and the display methodology.
A terrain model, for example, might be displayed
which is based upon thousands of accurately surveyed
points. Another model could also be displayed which is
based upon only several hundred. Without recourse to
ground truthing, or to the data themselves, it becomes very
difficult to realise which is the more accurate. As
disseminators of information to a data-naive public, we
must find techniques for displaying areas of fudged data
within our models, and attempt to educate people in the
skills of visual data analysis: an awareness of scale, an
understanding of the fact that lines on maps often
represent fuzzy boundaries, and a perception of the
limitations inherent in our data.
3.4 Conclusion
In conclusion, we believe that computer graphics should
carry a health warning. The motive for employing
graphical modelling and imaging systems in the
entertainment and advertising industries is the creation of
pictures that elicit certain kinds of responses from the
viewer, such as awe and wonder. Their role is to
manipulate the audience.
One can see examples of this in archaeology. Paul
Reilly (forthcoming) described a German project to
rebuild the great baroque Frauenkirche of Dresden, which
was destroyed by the firestorms that ravaged the city in the
aftermath of the allied bombing raids of 1945. The
church had become a symbol of national unity and the
project had a high public profile. As part of the campaign
to raise funds for the restoration, an award-winning
computer-generated tour of the Frauenkirche, restored to
its former glory, had been made to show potential
sponsors. The animation was accompanied by the music
of Johan Sebastian Bach playing on the Frauenkirche's
organ.
To quote Paul Reilly
'the image of archaeology that is being projected is
one that is dynamic, hi-tech and, unashamedly,
commercial' (Reilly forthcoming).
As a way of influencing large numbers of people,
computer visualization is a potentially powerful tool. On
the one hand it can give large numbers of people access to
the past, but on the other hand it gives tremendous power
to the custodians of the heritage. There are big differences
between research, education, entertainment and
propaganda, but it is not always easy to draw sharp lines
between them. Those who watched the frightening
televised virtual world of Oliver Stone's Wild Palms (BBC
2) will have witnessed a nightmare vision at one end of
this continuum. As the past becomes increasingly
commercialised and the graphics become increasingly
sophisticated this is a problem which we believe is likely
to grow in importance into the next century.
21
PAUL MILLER AND JULIAN RICHARDS
References
ALLEN, K. M. S., GREEN, S. W. & ZUBROW, E. B. W. (eds.) 1990. Interpreting
Space: CIS and archaeology, London. Taylor and
Francis.
BuRRiDGE, J., COLLINS, B. M., GALTIN, B. N., HALBERT, A. R. &
HEYWOOD.T. R. 1989. 'The WINSOM solid modeUer and its
application to data visualization', IBM Systems Journal, 28(4),
548-578.
CASTLEFORD, I. 1992. 'Archaeology, GIS, and the time dimension', in
G. Lock & J. Moffett (eds.). Computer Applications and
Quantitative Methods in Archaeology 1991, 95-106, British
Archaeological Reports (S) 577, Tempvs Reparatvm,. Oxford.
CORNFORTH,J. AND DAVIDSON, C. 1989. 'Picturing the Past',
Archaeological Computing Newsletter, 19, 1-7.
DEW, P., FERNANDO, L, HOLUMAN, N., LAWLER, M., MALHI, M. &
PARKIN, D. 1990. 'Illuminating chapters in history: computer
aided visualization for archaeological reconstruction',
Precirculated papers for Information Technology themes ax
World Archaeological Congress 2, Venezuela, September
1990, 1-8, Volume 3: Late papers, IBM UK Scientific Centre,
Winchester.
EFTELIORG, H. 1988. Computing Assisted Drafting and Design: new
technologies for old problems. Center for the Study of
Architecture, Bryn Mawr.
HEWISON, R. 1987. The Heritage Industry: Britain in a climate ofdecline,
London, Methuen.
KVAMME, K. L. 1992. 'Geographic Infonnation Systems and archaeology',
in G. Lock & J. Moffett (eds.). Computer Applications and
Quantitative Methods in Archaeology 1991, 77-84, British
Archaeological Reports (S) 577, Tempvs Reparatvm, Oxford.
LABROUSSE, A., & P. CORNON 1991. Viewing a Pyramid, Electricitée de
France, Paris.
LAVENDER, D., WALUS, A., BOWYER, A. & DAVENPORT, P. 1990, 'Solid
modelling of Roman Bath', Precirculated papers for
Information Technology themes at World Archaeological
Congress 2, Venezuela. September 1990, Volume 3,7-13, Late
papers, IBM UK Scientific Centre, Winchester.
MOSCATI, P. 1989. 'Archeologia e informatica: I'esperienza di Neapolis',
Rivista IBMXXV {\), 24-27.
REIU-Y, P. 1988. Data Visualization: recent advances in the application
of graphic systems to archeology, IBM UKSC report 185,
March 1988, IBM, Winchester.
REHiY, P. 1992. 'Three-dimensional modelling and primary archaeological
data', P. Reilly & S. P. Q. Rahtz (eds). Archaeology and the
Information Age: a global perspective, 147-176, Routledge,
London.
REILLY, P. (forthcoming). 'Access to insights: stimulating archaeological
visualization in the 1990's', in A. Suhadja & K. Biro (eds.) The
future ofour Past '95, Hungarian National Museums, Budapest.
REILLY, P. & Rahtz, S. P. Q. 1992., (eds.) Archaeology and the
Information Age: a globalperspective, Routiedge, London.
SOPRINTENDENZA ARCHEOLOGL\ PER LE PROVINCIE DI SASSARI E NUORO
1989. SIPIA - Progetto SITAG Archaeologia del Territorio.
Territoria dell' Archeologia: immagini di un' esperienza di
catalogazione informatica dei béni culturali délia Gallura,
Chiarella-Sassari. Tempio Pausania.
SMITH, 1. 1985. 'Sid and Dora's Bath show pulls in the aowd'. Computing,
27 June 1985,7-8.
TUFTE, E. R. 1990. Envisioning Information, Graphics Press, Cheshire,
CO.
W00D,J. & CHAPMAN, G. 1992. 'Three-dimensional computer
visualization of historic buildings - with particular reference to
reconstruction modelling' in P. Reilly & S. P. Q. Rahtz (eds.)
Archaeology and the Information Age: a global perspective,
123-146, Routledge, London.
WOODWARK, J. R. 1991. 'Reconstructing history with computer graphics',
IEEE Computer Graphics arui Applications, January 1991,
18-20.
22