Which three of the following statements about user interfaces are true?

Select one or more:

The design of Uls is exclusively concerned with input and output devices.

When designing a device, it is important to match the person to the technology, not the technology to the person.

A UI should not be designed with only one type of user in mind; it should serve a diverse range of users with varying needs.

The concept of 'separability' means that changes can be made to the programmer's model of the system without affecting the user's model.

$HCl$ techniques can be used to resolve problems caused by the mismatch between user models and programmer models.