Rapid prototyping
Summary
In rapid prototyping interactive prototypes are developed
which can be quickly replaced or changed in line with design
feedback. This feedback may be derived from colleagues or
users as they work with the prototype to accomplish set tasks.
This method is concerned with developing different proposed
concepts through software or hardware prototypes, and evaluating
them. In general the process is termed ‘rapid’ prototyping.
The development of a simulation or prototype of the future
system can be very helpful, allowing users to visualise the
system and provide feedback on it. Thus it can be used to
clarify user requirements options. Later on in the lifecycle,
it can also be used to specify details of the user interface
to be included in the future system.
Within software engineering circles the method is closely
associated with user interface management systems and various
design support tools. The latter tools offer the designer
libraries of process and graphical interface elements for
defining the software’s logical structure and ‘look-and-feel’.
Here the title refers to an approach adopted by software developers
in which the prototypes exhibit a higher fidelity with the
end product than those created as part of other methods such
as paper prototyping.
Benefits
- Gives users (especially the general public) a tangible
demonstration of what the system is about.
- Permits the swift development of interactive software
prototypes.
- Prototypes created by this method have a high fidelity
with the final product
- The prototypes created under this method support metric-based
evaluations
Method
A general procedure for adopting the rapid prototyping method
is outlined below.
- Allow enough time to create the prototype. If the prototype
is to be evaluated with users then allow time to design
relevant tasks, recruit the users, evaluate the prototype
and report the results.
- Assemble the necessary equipment, including the hardware
and software tools necessary to create the interactive prototype.
- Develop the prototype itself.
- Select appropriate users to test the prototype, trying
to cover the range of users within the target population.
A facilitator will also be required to instruct the users
and run the evaluation.
- Prepare realistic tasks to occupy the users as they work
with the prototype.
- Pilot the evaluation procedure and ensure the prototype
can be used to accomplish the tasks.
- Ensure recording facilities are available and functioning.
- Conduct each session. The facilitator instructs the user
to work through the allocated tasks, interacting with, and
responding to, the system as appropriate.
- If necessary additional information can be obtained by
interviewing users following their use of the prototype.
Debrief and thank the user.
- Analyse the obtained information and then summarise the
observations and user evaluations. Determine the themes
and severity of the problems identified.
- Summarise design implications and recommendations for
improvements and feed back to design team. Video recordings
can support this.
- Where necessary refine the prototype and repeat the above
process.
When using this method, avoid spending too long on the development
of initial prototypes as user evaluation may result in substantial
changes. Also, avoid making the prototype too polished as
this may force users to accept it as finished. Do not put
in features that will raise the users expectations but which
are unlikely to be achieved with the real system (e.g. too
fast response times, too sophisticated graphics) and do not
put too much effort into particular features (e.g. animations)
which may not be required.
Be aware that the method requires software development skills.
Also, although rapid, the method can often be more time consuming
than other approaches and that resources required are greater
than paper and pens due to the need for software and hardware.
More Information
Many tools exist for producing rapid prototypes ranging from
a sequence of Microsoft PowerPoint screens, to script based
programming systems such as HyperCard, Toolbook and Visual
Basic that can help to create a software prototype. The method
requires more sophisticated technical resources than is the
case with low-fidelity prototyping methods that rely on paper
materials. An additional cost of use is the level of human
expertise required to master the supporting development tools,
along with the time necessary to implement a software prototype.
Alternative Methods
Alternative methods that can be used earlier in the lifecycle
are:
Background Reading
Andrews, D.C. (1991) JAD: A crucial dimension for rapid applications
development’. Journal of systems management, March 23-31.
Isensee, S, & J Rudd (1966) The Art of Rapid Prototyping.
International Thomson Computer Press, London. |
