What is a scenario and how is it used in UID design?

• A. A list of system constraints to limit design options.
• B. A narrative of a user performing a task to guide requirements and test usability.
• C. A high-fidelity prototype used for coding.
• D. A collection of pixel-perfect mockups.

Answer: (B)

In UID design, a scenario is a user-centered narrative that describes someone trying to complete a task with the product, including their goal, the context, the steps they take, and the expected outcome. It guides requirements by focusing on what the user needs to accomplish and how the system should support them, helping designers decide which features are essential and what constraints matter. Scenarios also underpin usability testing: by following the story, testers can see whether the interface supports each step, where users may encounter friction, and how the flow could be improved. This keeps the design grounded in real user tasks rather than starting from constraints or visuals. For example, a scenario might describe a student needing to add a course to a calendar on a mobile app, detailing the actions, what information is shown, and how the app should respond to errors. The other options describe constraints, coding prototypes, or pixel-perfect mockups—artifacts that come later or address different aspects, not the narrative of user activity used to shape requirements and test usability.