Back to Phase 3: Detailed Design

3.5.1.2 Prototyping

A prototype is a simulation of the intended presentation and functionality of the system. It allows user validation prior to committing to build, and demonstrates its intended functionality to the development team. In the detailed design phase, a prototype would typically be based on high-fidelity wireframes or comps.

Requirements

• High-fidelity wireframes or comps to act as source material.
• Use cases the prototype is meant to simulate.
• User stories or similar for detailed requirements or acceptance criteria the prototype should follow.

Product/output

A high-fidelity prototype should be digital and interactive, even if only for highly specific click-paths. The fidelity at this point should be close enough to an exact representation of the intended final product, that testing of the prototype should result in reasonably accurate user performance data (e.g. time to perform a given task).

Practical considerations

• If usability testing goals do not require the prototype to dynamically respond to user inputs, a prototype comprised simply of clickable static interface images (i.e. visual design comps) can suffice.
• It is generally better to prototype small units of an experience such as key pages, sections or features than to manage one comprehensive prototype. This keeps prototypes manageable and focused, and minimizes need for additional time in refactoring patterns and interactions across a larger whole, especially when the delivery focus is narrower.

Reference

• Prototyping https://www.usability.gov/how-to-and-tools/methods/prototyping.html