What is the primary focus of black-box test design techniques?

The primary focus of black-box test design techniques is on the input-output functionality of the system being tested. These techniques emphasize examining the external behavior of the software application rather than its internal workings. Testers utilize black-box techniques to ensure that given a set of inputs, the system produces the expected outputs according to specified requirements or user stories.

This approach allows testers to validate the functionality from an end-user perspective, as they typically do not have access to or knowledge of the internal code structure or design. Black-box testing can assess various aspects of the software, including its business logic, data handling, and integration with other systems, as long as the inputs and expected outcomes are clearly defined.

While user interface design factors may play a role in shaping the inputs and outputs, the core of black-box testing remains focused on the correct functioning of the application based on input-output pairs. Similarly, hardware performance is typically analyzed through performance testing, which is distinct from the black-box focus on functional requirements.