The design of those aspects of a system that the user perceives and communicates
with.
Hypothesis : in new media the system is interactive
How to make the interaction efficient ?
Design for unstable media
HCI Human Computer Interface
Man-machine interface
Information engineers
Usability
Usability and Design of the Human Computer Interface (there is a DCS course of this name)
Usability
The usability of an interface is the measure of the effectiveness, efficiency
and satisfaction with which specified users can achieve specified goals in a
particular environment with that interface
Sometimes really easy to measure : "How much time do you need to program
your VCR ?"