A woman teaching girls in Afghanistan how to use computers. Human use of computers is a major focus of the field of HCI. Because human–computer interaction studies a human and a machine in conjunction, it draws from supporting knowledge on both the machine and the human side. On the machine side, techniques in computer graphics, operating systems, programming languages, and development environments are relevant. On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology, social psychology, and human factors such as computer user satisfaction are relevant. Engineering and design methods are also relevant. Poorly designed human-machine interfaces can lead to many unexpected problems. HCI Goals HCI (Human Computer Interaction) aims to improve the interactions between users and computers by making computers more usable and receptive to users' needs. Differences with related fields Design 1. 2. 3. 4.