Video
Prototyping
Primary Reference Sources
Vertelney, L (1989) Using video to prototype user interfaces. SIGCHI
Bulletin, V21 (2), pp 57-61.
Summary description
This method allows designers to create a video-based simulation of interface
functionality using simple materials and equipment. Interface elements
are created using paper, pens, acetates etc. For example a start state
for the interface is recorded using a standard camcorder. The movements
of a mouse pointer over menus may then be simulated by stopping and starting
the camcorder as interfaces elements are moved, taken away and added. Users
do not directly interact with the prototype although they can view and
comment on the completed video-based simulation.
Typical Application Areas
Wide application potential, particularly suited for simulating interface
functionality. However, it must be possible to simulate the interface elements
with basic materials. The method is relevant in the early stages of the
design cycle to demonstrate design options and concepts.
Benefits
Usability problems can be detected at a very early stage in the design
process (before a commitment to code has been made). Provides a dynamic
simulation of interface elements that can be viewed and commented on by
both design teams and intended users. Minimal resources and materials are
required to convey product feel. The technique can be utilised by those
with little or no human factors expertise.
Limitations
Staff familiar with the functionality of the intended system are required
to create the video prototype. The method does not actually capture a user
interacting with the prototype. Because of the use of simple materials,
video prototypes do not support the evaluation of fine design detail.
Cost of use
As with paper prototyping only simple materials are required to create
the elements of the prototype to be committed to video-tape. These include
paper, acetate, pens and adhesives. A video camera is also required to
capture and replay a simulation. The method calls for two people, one to
manipulate the interface elements and so operate the computer and the other
to control the camera. Little video production expertise is required, although
it could be time-consuming to create more complex sequences using stop-motion
animation. Regular use would incur basic costs for paper materials and
video-tapes.
Costs of Acquisition
Compulsory training is not specified, although the technique may require
some experience to reach competency in the basic principles.
Suitability for requirements engineering in Telematics:
This is a novel and interesting method, the principles of which are
adopted in some sectors of industry. However, it lacks the interactive
element of other prototyping methods and would perhaps be most suited for
demonstration purposes where larger audiences are involved.
How to get it
This is not described as a proprietary method. It has been practised within
America, particularly at US West and Apple. A good start is the reference
cited above; SINTEF has experience of
this method in the EUSC.
Detailed description of method
The general procedure relating to this method is outlined below. The method
parallels that described for paper prototyping in several respects, although
the emphasis on creating a video-based simulation is a distinct feature,
as is the absence of users who directly interact with the prototype.
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First, allow enough time to create the prototype, design some scenarios
of use for demonstration purposes, and produce the video-based simulation.
It should be remembered that even brief sequences of stop-start animation
can be time consuming.
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Assemble the necessary materials. Construct the paper prototype, using
separate stock for menus, dialogue boxes and any element that moves or
changes appearance. A paper-based mouse pointer for instance can be attached
to the end of a strip of acetate so that it can be moved without the operators
hands appearing on the video recording.
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The person manipulating the interface elements should practice playing
the role of the computer.
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Ensure recording facilities are available and functioning. Ideally the
camera should point directly at the prototype, perhaps by being mounted
above a table where the materials are placed.
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One person should manipulate the elements of the paper prototype while
another person controls the video camera. For example a menu selection
can be captured by initially filming a shot of the paper desktop and subsequently
filming a brief sequence as the mouse pointer is moved on a transparent
arm to a menu item. The video camera is then paused while a paper representation
of a menu is placed under the camera, filming then continues while the
mouse pointer passes down the menu items.
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Once completed the video-based prototype can be shown to design teams as
well as intended users to solicit evaluative feedback. Several video prototypes
can be created and shown to an audience in order to explore different design
options.
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Where necessary the prototype can be refined and the above process repeated.
The use of video prototypes supports the exploration of design options
by providing a dynamic simulation which can be shown to both potential
users and colleagues. This can result in recommendations for the refinement
of the initial prototype.