Requirements discovery is often an iterative process in which developers create prototypes in order to elicit reactions from potential stakeholders. In so-called "rapid prototyping" approaches to requirements discovery, developers create prototypes designed to demonstrate specific aspects of functional capabilities that might ultimately be implemented. Scenario-based observational studies are often used to assess the utility of the functions demonstrated by the prototype.
Characteristics of the intended mode of use (2.1.4/160)
Utility (2.1.1.1.5/176)
Usability (2.2.3/603)