User-Interface Prototypes may be formal or informal, executable or non-executable, low fidelity or high-fidelity
prototypes. For example, a User-Interface Prototype may range from a series of pictures represent screen captures of
some interactive HTML pages. The format the UI prototype takes is not the issue. What is important to keep in mind is
the purpose of the User-Interface Prototype (to explore and/or validate a user-interface design), and what skills are
required to produce the prototype (a User-Interface Prototype requires some user-interface design skills).
Decide whether a prototype is suitable for your project. Decide on how much of the user interface to prototype,
and the depth and realism of any interactivity. Decide whether the prototype is purely throwaway, or whether some
aspects are intended to evolve into the end product.
Keep in mind that in order to achieve the goal of early testing of the user interface, the prototype must be
significantly cheaper to develop than the real system, while having enough capabilities to be able to support a
meaningful use test.