Which method involves participants directly interacting with a low-fidelity prototype during testing?

A paper prototype is a method that entails participants directly interacting with a low-fidelity prototype during testing. This approach involves creating simple, hand-drawn representations of the user interface and functionalities, which participants can manipulate in a real-world scenario. By utilizing paper prototypes, designers are able to quickly gather valuable feedback on the design and user flow without the time and resources required for high-fidelity prototypes.

Participants can engage meaningfully during these sessions, simulating actions such as clicking buttons or navigating through screens, which helps to identify usability issues early in the design process. This hands-on interaction allows testers to observe user behavior, capture insights, and make iterative improvements based on direct user feedback, making paper prototypes an essential tool in the UX design process.

The other methods mentioned, while related to prototyping and testing, do not specifically emphasize interaction with low-fidelity prototypes in the same way that paper prototypes do. Functions like wireframe testing or usability testing may involve more developed or functional prototypes.