Ariel is an example of a new approach to user interfaces
called Augmented Reality (see Wellner et al., 1993, Mackay
et al., 1993). The goal is toallow users to continue to use
the ordinary, everyday objects they encounter in their daily
work, and then toenhance or augment them with
functionality from the computer. Ariel is designed to
augment the use of a particular type of paper
document:engineering drawings. Computer information
(menus, multimedia annotations,access to a media space) is
projected onto a drawing and users can interact with both
the projected information and the paper drawing.
The design of Ariel is based on studies of users in a
distributed cooperative work setting (the construction of a
bridge) combined with a scenario-based design approach in
which users contribute to the development of design
scenarios. This video shows thethird Ariel prototype.
Future versions will continue to evolve, based on input from
users when the system is installed at the work site.
EUROCODE PROJECT
Ariel is part of a three-year European ESPRIT project
called EuroCODE,which provides an object-oriented, open
development environment for thedevelopment of
distributed, multimedia cooperative work applications.
Theconsortium includes partners from Denmark (Aarhus
University, Jdysk Telphon, Storb�lt), Norway
(NorskRegnecentral), Germany (GMD, Empirica, CAP
Debis), and the United Kingdom(ICL, Nexor and Rank
Xerox).
A key goal of the project is to create innovative tech-
nologies for realusers. We are working with the engineers
responsible for the construction of the world's longest
suspension bridge, which spans the Great Belt (Storb�lt)
waterway that divides Denmark. By studying their work
practices, we have been able to ground the development of
the Ariel technology in real-world problems. We are
experimenting with �scenario-based design', in which we
work directly with users to create scenarios of
workactivities and then co-develop technologies with them
to support thoseactivities (Mackay and B�dker (1994).
One of Rank Xerox's contributions to the project is the
�HighRoad Demonstrator' (Mackay et al., 1993), or Ariel,
which provides high bandwidth communication facilities
for the engineering supervisors.Ariel's design is influenced
both by technologies developed at Rank Xerox,particularly
the media space (Gaver et al., 1992) and the Digital
Desk(Wellner, 1992) and by our studies of users at the
site.
USER STUDIES
We interviewed people ina variety of positions at the Great
Belt and selected a group of supervisors as our target user
group. We accompanied them on trips to the bridge sites
and observed them in the course of their daily activities.
Wediscovered that most of their work centers around the
use of engineering drawings: updating them, checking
them, and comparing them with the real construction. They
spend much of their time travelling from site to site.
Although they all have computers on theirdesks, they rarely
refer to the on-line versions of the drawings. Instead, they
keep personalized paper copies,which they annotate. They
also record information during their site visits,either with a
Dictaphone for verbal comments or a video camcorder,
torecord problems or inconsistencies between the
construction and the drawing.
Although they find paper very convenient, it can also cause
problems. Amajor issue is the mismatch between the paper
and the on-line, officially approved CAD version. Given
tight schedules, small changes are often only recorded on
their personal drawings. Approval and update of theon-line
version (which can take three months) occurs later. If
theengineers actually waited for formal approval for every
minor change, the bridge would never get built.
The result is that these small changes are often omitted
from the final,approved CAD drawings. This was clearly
the case when, in the review of theCAD drawings for the
recently-completed west section of the bridge,
they discovered many discrepancies between the �final'
drawings and what was actually built.
For the most part, the relevant people are all aware of the
minor changes. They copy their sketches and notes and fax
them to each other. However, the information is sometimes
lost, particularly when someone is out of town, or misses an
important meeting.
SCENARIO-BASED DESIGN OF ARIEL
The observation that engineering documents are central to
the engineer's work caused us to revise our initial vision of
Ariel as an office-based media space. Instead, we used a
Digital Desk style of interface, centered around the
engineering drawings, and added amedia space. This
avoids forcing supervisors to change their work
patterns while still providing them with significantly new
functionality and betteraccess to each other.Their
personalized engineering drawings become the interface to
thecomputer system.
We invited users and other members of the EuroCODE
project to participatein a series of workshops, in which we
developed scenarios of daily work practices and
brainstormed ideas about how to better support those
practices with new technologies. We created a video
prototype that illustrated several user scenarios and howed
it to the users. Based on their reactions (and innovative
ideas!), we developed several prototypes on different
hardware and software platforms. This allowed us to
explore both software user interface issues and different
hardware options.
We brought potential users to our laboratory in England
and got their feedback on some of the possible interfaces.
We also created a portable version of Ariel which we
broughtto the Great Belt and ran a workshop for users. The
current version of Ariel, shown in the videotape, is
undergoing revision and is scheduled to be installed and
tested with real users at the bridge site in the fall and winter
of 1994-1995.
ARIEL TECHNOLOGY
Ariel is not a single system, but rather an exploration of a
design space. However, all versions of Ariel must address
how to identify individual engineering drawings and relate
them to on-line versions, capture and respond to user
commands, record information supplied by the user
(including sketches, hand-written notes,audio and video
clips), project information (menus, user information)
ontothe paper drawings, and provide live, audio/video
communication between various bridge and on-shore sites.
TheMacintosh version of Ariel shown in the video includes
the following:
- Screen projection:
- an active-matrix,thin-film transistor (TFT) color LCD
projection panel mounted on anoverhead projector
(Proxima Ovation 820, 640x480 pixels with 2
millioncolors)
- Input from the engineeringdrawing:
- video camera for capturing the x-y position of a pointer
(Proxima Cyclops,added to the LCD projection panel).
The pointer can be any source of redlight: a red LED; a
laser beam; the red light on the bar code readerwand
- switchable LED on a paper clip and on a magnet
- bar-code reader (Worthington)
- hand-held scanner (Logitech ScanMan 32)
- A2 digitizing tablet (Wacom)
- video camera and video grabber (using a NuBus
expansion slot)
<./ul>
- Computer Hardware
- Apple MacintoshPowerBook 180 (portable version)
- Apple Macintosh Quadra series
- Communications
- ATM (highbandwidth) or ISDN (lower bandwidth) lines
- Software
- HyperCard 2.2
- Custom software to handle input devices
- Special Features
- hypermedia linkingof multimedia annotations
- detection of the user's current position on the drawing
codes for commands and drawing identification
- access to live video connections via a media space
- virtual paper window: a computer window is projected
on to awhite piece of paper with a switchable LED
attached. The computer tracksthe position of the virtual
window and projects the computer window on topof it.
ACKNOWLEDGEMENTS
Thanks to P. Wellner, M. Beaudouin-Lafon, K. Carter, C.
Ma, T. Slater, Q.Stafford-Fraser and G. Velay for their
technical work on previous versionsof Ariel and Ariel
videotapes. Also, thanks to the EuroCODE
partners,particularly T.Aargard, L. Elstrom, P. Holmes, H.
Lovett and P. Sorgaard for their design contributions.
Thanksalso to M. Beaudouin-Lafon at LRI and G.
Chastagn� at LIMSI,Universit� de Paris-Sud for assistance
with the video production. Finally, thanks toour users, who
have contributed greatly to Ariel's design and to
ourunderstanding of the use of engineering documents.
References
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W.Gaver, T.Moran,A.MacLean, L.L�vstrand, P.Dourish,
K.Carter, and W.Buxton (1992)Realizing a video
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ceedings of the CHI'92Conference on Human Factors
in Computing Systems, Monterey, CA: ACM Press.
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Mackay, W., Faber, L., Launianen, P. and Pagani, D.
(1993) Design of theHigh Road Demonstrator, D4.4,
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Mackay, W., Velay, G., Carter, K., Ma, C., and Pagani, D.
(1993) AugmentingReality: Adding Computational
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Mackay, W. and B�dker, S. (1994) Scenario-Based Design
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