Low-fidelity prototypes (Lo-Fi) and high-fidelity prototypes (Hi-Fi) are both very important when testing how users interact with a design.

Lo-Fi Prototypes:

• They are cheap to make and easy to change.
• These prototypes are used early in the design process.
• About 70% of problems with usability (how easy it is to use something) can be found at this stage.

Hi-Fi Prototypes:

• They look and feel more like the final product.
• Users can give better feedback because it’s more realistic.
• Around 85% of tasks that users want to do can be completed smoothly with these prototypes. This helps ensure that the design meets what users expect.

In summary, the choice between Lo-Fi and Hi-Fi prototypes greatly affects how usable the design will be and the overall direction of the project.