There is currently no agreed upon definition of the range of topics which form the area of human-computer interaction. Yet we need a characterization of the field if we are to study it. The Association of Computer Machinery (ACM) offers a good working definition :
Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them1.
The following two short videos give short explanations of User Experience Design (UX) and User Interface Design (UI)
The focus is on interaction and specifically on interaction between one or more humans and one or more 'machines'. The classical situation that comes to mind is a person using using a keyboard and mouse, and looking at a screen. But it is clear that varying what is meant by interaction, human, and machine leads to a rich space of possible topics including software, cell phone apps, web pages, car dashboards, ATM machines, video game consoles, household appliances, etc.
In our definitions the term human could mean a group of humans or an organization, so we may consider interfaces for distributed systems, social media, communications systems, or the nature of cooperative work.
The Design of Everyday Things is a best-selling book by cognitive scientist and usability engineer Donald Norman about how design serves as the communication between object and user, and how to optimize that conduit of communication in order to make the experience of using the object pleasurable.
Norman uses case studies to describe the psychology behind what he deems good and bad design, and proposes design principles. The book spans several disciplines including behavioral psychology, ergonomics, and design practice.
The HCI masters programs here at SUNY Oswego integrate service and design thinking into a rigorous, cross-disciplinary human-computer interaction curriculum that prepares our students to design and guide the future of human and technology interactions. Our program provides students with the practical skills and theoretical understandings they need to develop successful careers related to human-computer interaction, user experience (UX) design and user-centered research.
1. Hewett, Baecker, Card, Carey, Gasen, Mantei, Perlman, Strong and Verplank, ACM SIGCHI Curricula for Human-Computer Interaction, ACM SIGCHI, 1996, Available at : http://old.sigchi.org/cdg/cdg2.html