In what scenario is user feedback essential during requirements gathering?

User feedback is particularly essential when identifying non-functional requirements because these requirements often relate to aspects such as performance, usability, reliability, and scalability, which can be subjective and influenced by user experiences and expectations. Non-functional requirements define how a system should behave rather than what the system should do, meaning they must resonate with the actual expectations of users.

Gathering user feedback helps ensure that non-functional requirements reflect real-world usage scenarios and user needs, which is crucial for the success of the system. Users may have insights about performance thresholds, usability preferences, and other qualitative aspects that are not typically captured in purely technical specifications. Engaging users during this phase allows for a more comprehensive understanding of the necessary qualities that the system must meet to provide value to its users.

In contrast, scenarios where technical specifications are already defined might limit the opportunity for user feedback to influence the requirements. Similarly, while user feedback is important for confirming acceptance criteria and documenting functional requirements, these do not encompass the broader, more subjective domain of non-functional requirements where user input can significantly shape outcomes.