Explain the difference between verification and validation in the context of a rehab exoskeleton's software.

• A. Verification checks that software was built correctly against specifications; validation confirms the device meets user needs in real-world use.
• B. Validation checks that software was built correctly against specifications; verification confirms the device meets user needs in real-world use.
• C. Verification checks that the device meets user needs in real-world use; validation checks software against specifications.
• D. Verification is post-market only, while validation is during design.

Answer: (C)

In this context, the main idea is to separate real-world performance from conformance to design. The correct pairing says that verification is about confirming the device actually meets user needs when used in real settings—safety, comfort, and effectiveness during typical activities the user would perform. Validation, on the other hand, checks that the software follows its defined specifications and design intentions—ensuring the implemented algorithms, interfaces, timing, and safety constraints match what was planned.

So, for a rehab exoskeleton, verification involves testing in real-use scenarios to see if the device truly helps the user as intended across various tasks, environments, and user differences. Validation involves examining the software itself to ensure it was built to the specified requirements and design documents—checking that the code and software behaviors align with the intended functions and constraints. Both are important, but this distinction emphasizes that real-world performance is about meeting user needs, while software conformance is about meeting the specified design.