Our first assigment is to propose two interfaces. We must describe  the interface as well as identify and distinguish the positive and negative details of both of them. 

A Good interface

The Screen locker interface.This interface is commonly known for fingerprint .Mostly known as a security procedure although it also increase user usability.

Unlocking a mobile phone with a fingerprint procedure on lock screen just turn the locking procedure much more smooth,fast ultimatly safe.Unless someone managed to get your fingerprint there is not a downside. 

A Bad interface

When Windows 8 arrived on small portable devices such as hybrid or tablets at some point the virtual keyboard overplaced the type area.The user could not see what was typing.This problem is still today on Windows 10 a issue.It's not certain that in every app or web page it will be responsive.

Virtual keyboard interface it's particular mandatory on devices that do not support physical keyboards.In case of a responsive malfunction it can be frustrating hence decreasing user usability.