In producing a concept, the objective is to demonstrate

• How it can be achieved technically
• The potential look and feel
• The user or market need being addressed
• The value to the business

The first two objectives often involve some form of physical or virtual prototyping, allowing rapid user feedback and validation of the last two. The aim of any prototype created is to get feedback and buy-in from key stakeholders (external and internal), so the best approach(es) to achieve this aim should be chosen.

Prototypes can be evaluated against the design requirements using techniques such as expert appraisal and user testing.

For more explanation of these tools, see the Evaluation tools and Task analysis sections within Knowledge & Tools.