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| Menus: how to make menus
tangible? |
| Investigating menu designs for
Build-it system |
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| by Fred Voorhorst, Helmut Krueger & Martin Bischel (Zürich, 2000) |
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| Build-It
[2, 5] is an AR based desktop tool based on intuitive
manipulation for the support of planning and configuration
tasks. Build-It presents the user with two views:
a table view showing the virtual environment in
plan, and a wall projection, showing the virtual
environment in perspective. The plan view contains
a (virtual) camera that determines the image presented
on the wall view. Build-it has a so-called graspable
user interface. An interface is called graspable
when each function of the interface is operated
by means of a dedicated physical device. The device
a function is operated with serves as a graspable
function [1]. |
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| The technical implementation of
Build-it (two projectors and an infrared tracking
system) can be used to the advantage of the implementation
of menus. Both the tracking of the bricks and the
projecting of the computer image is done from above
the table surface. Augmented reality systems (AR)
provide the possibility to explore the use of menus
in an unconstraint way. |
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| A possible implementation for
an AR system would be selection directly from a
catalog and dragging it on the desktop. |
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| In a small experiment two principles
of implementing menus were tested. First, with respect
to selection: a menu can be accessed either direct
or through a handler. Second, with respect to interaction:
the menu or handler either is virtual or real. |
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| Subjects were shown a configuration
which they were asked to rebuild as accurately as
possible. Three subjects participated in the experiment.
Graspable, i.e. easily accessible, menus were assumed
to have the advantage over non-graspable menus.
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Although subjects were asked to
be as good as possible, and not as fast as possible,
one could expect the amount of time needed to be
less for easy conditions compared to difficult conditions.
However, no time differences were found (figure
on the right).
The figure on the left gives an overview of the
number of times subjects switched between menus.
These results indicate two types of strategies.
Strategy 1 is the optimization of menu access and
is used when menus are difficult accessible (condition
4). Subjects optimize the number of changes between
menus by accessing each menu only once. Strategy
2 is the optimization of task performance and is
used when menus are easily accessible (e.g. condition
2). Subjects selected freely from different menus,
depending on the menu item that is needed. |
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| Results of the experiment demonstrate
the advantage of making menus graspable but also
show the importance of making perceivable this grasp-ability
as not all users will fully explore the possibilities
of the system. Most interestingly, depending on how the interface was offered the subjects seemed to develop a different strategy. |
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| References |
[1] Fitzmaurice, G. W., Buxton,
W., 1997, An empirical evaluation of graspable user-interfaces:
towards specialized space-multiplexed input: CHI
97: Looking to the future.
[2] Fjeld, M., Bichsel, M., Rauterberg, M., (1998),
Build-It: A brick based tool for direct interaction:
Engineering, Psychology and Cognitive Ergonomics,
v.
[3] Ashgate, Hampshire, 5 p. 3. Hummels, C. J.,
Stappers, P.J., 1998, Meaningful gestures for human
computer interaction: beyond hand postures: Proceedings
3rd Int. Conference on Automatic Face & Hand recognition,
p. 591 - 596.
[4] Milgram, P., Takemura, H., Utsumi, A. & Kishino,
K., (1994) Augmented Reality, a class of displays
on the reality-virtuality continuum: SPIE, v. 2351.
[5] Rauterberg, M., Fjeld, M., Krueger, H., Bichsel,
M., Leonhardt, U. & Meier, M., 1997, BUILD-IT: a
video-based interaction technique of a planning
tool for construction and design.: Proceedings of
Work With Display Units -- WWDU'97, p. 175-176.
[6] Voorhorst, F.A & Krueger, H. (1999) User-friendly
by making the interface graspable. In: Proceedings
of 8th HCI conference. Eds: M.J. Smith, G. Salvendy
& R.J. Koubek. Volume 1. Pp.416-420
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| This works was presented as a
short paper at the CHI2000: the full CHI2000
paper (56kb) |
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| Build-it® is trademark of the company TELLWARE GmbH |
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