Human-computer interaction

Human-computer interaction (HCI) or, alternatively, computer-human interaction (symbolized as Χ χ Chi, the 22nd letter of the Greek alphabet) is the study of interaction between people (users) and computers. It is an interdisciplinary subject, relating computer science with many other fields of study and research. Interaction between users and computers occurs at the user interface (or simply interface), which includes both software and hardware, for example, general purpose computer peripherals and large-scale mechanical systems such as aircraft and power plants.

Interdisciplinary aspects
Combined with computer science and information technology are fields including:
 * Aesthetics
 * Anthropology
 * Artificial intelligence
 * Cognitive science
 * Computer vision
 * Design
 * Ergonomics
 * Human factors
 * Library and information science
 * Philosophy
 * Phenomenology
 * Psychology
 * Social psychology
 * Sociology
 * Speech-language pathology

Goals
A basic goal of HCI is to improve the interaction between users and computers by making computers more user-friendly and receptive to the user's needs. Specifically, HCI is concerned with
 * methodologies and processes for designing interfaces (i.e., given a task and a class of users, design the best possible interface within given constraints, optimizing for a desired property such as learnability or efficiency of use)
 * methods for implementing interfaces (e.g. software toolkits and libraries; efficient algorithms)
 * techniques for evaluating and comparing interfaces
 * developing new interfaces and interaction techniques
 * developing descriptive and predictive models and theories of interaction

A long term goal of HCI is to design systems that minimize the barrier between the human's cognitive model of what they want to accomplish and the computer's understanding of the user's task (see CSCW).

Professional practitioners in HCI are usually designers concerned with the practical application of design methodologies to real-world problems. Their work often revolves around designing graphical user interfaces and web interfaces.

Researchers in HCI are interested in developing new design methodologies, experimenting with new hardware devices, prototyping new software systems, exploring new paradigms for interaction, and developing models and theories of interaction.

Terminology

 * HCI vs CHI. The acronym CHI (pronounced kai), for computer-human interaction, has been used to refer to this field, perhaps more frequently in the past than now. However, researchers and practitioners now refer to their field of study as HCI (pronounced as an initialism), which perhaps rose in popularity partly because of the notion that the human, and the human's needs and time, should be considered first, and are more important than the machine's.  This notion became increasingly relevant towards the end of the 20th century as computers became increasingly inexpensive (as did CPU time), small, and powerful. Since the turn of the millennium, the field of human-centered computing has emerged as an even more pronounced focus on understanding human beings as actors within socio-technical systems.


 * Usability vs Usefulness. Design methodologies in HCI aim to create user interfaces that are usable, i.e. that can be operated with ease and efficiency. However, an even more basic requirement is that the user interface be useful, i.e. that it allow the user to complete relevant tasks.


 * Intuitive and Natural. Software products are often touted by marketeers as being "intuitive" and "natural" to use, often simply because they have a graphical user interface. Many researchers in HCI view such claims as unfounded (e.g. a poorly designed GUI may be very unusable), and some object to the use of the words intuitive and natural as vague and/or misleading, since these are very context-dependent terms.


 * Data Density and Information Absorption. The rapid growth in the density of computer screen real estate has created an opportunity to accelerate "information absorption" to much higher levels. Classic "data density" on a computer is 50-100 data points, recent advances in data visualization enable thousands of data points to be presented in forms which can be rapidly absorbed. Interfaces such as virtual reality will give further growth the potential density of information presented.

Design methodologies
A number of diverse methodologies outlining techniques for human-computer interaction design have emerged since the rise of the field in the 1980s. Most design methodologies stem from a model for how users, designers, and technical systems interact. Early methodologies, for example, treated users' cognitive processes as predictable and quantifiable and encouraged design practitioners to look to cognitive science results in areas such as memory and attention when designing user interfaces. Modern models tend to focus on a constant feedback and conversation between users, designers, and engineers and push for technical systems to be wrapped around the types of experiences users want to have, rather than wrapping user experience around a completed system.


 * User-centered design: User-centered design (UCD) is a modern, widely practiced design philosophy rooted in the idea that users must take center-stage in the design of any computer system. Users, designers, and technical practitioners work together to articulate the wants, needs, and limitations of the user and create a system that addresses these elements. Often, user-centered design projects are informed by ethnographic studies of the environments in which users will be interacting with the system.


 * Contextual Usability: Contextual Usability (CU) is a framework also arising from the ‘ethnographic turn’ in the human, social and computer sciences and during the 1990s, although statistical direct observation methods and system-logging also play a role in its analysis. CU seeks to privilege neither users nor technology within a use or usage process. As such it links usability, ergonomics and user experience design to ideas emerging from social studies of science and technology such as actor-networks and sociotechnical constituencies . It seeks to locate motivations, instances and circumstances of use against social, cognitive and cultural influences. These can promote or negate the formation of usage patterns and periodicities. It views usability as a project (in design) and an experience (in use), one which is 'just outside' the boundaries of design affect and 'just inside' a potential or actual users whole experience of an artifact or service. It generates data according to a quadrant which includes use, usability, usage, and usefulness. It is most associated with the work of Derek William Nicoll.

Academic conferences
One of the top academic conferences for new research in human-computer interaction, especially within computer science, is the annually held ACM's Conference on Human Factors in Computing Systems, usually referred to by its short name CHI (pronounced kai, or khai). CHI is organized by ACM SIGCHI Special Interest Group on Computer-Human Interaction. CHI is a large, highly competitive conference, with thousands of attendants, and is quite broad in scope.


 * HCI International


 * CHI 2006
 * CHI 2005
 * CHI 2004

There are also dozens of smaller, more specialized HCI-related conferences held around the world each year.
 * UIST 2005 &mdash; ACM Symposium on User Interface Software and Technology
 * NIME &mdash; International Conference on New Interfaces for Musical Expression
 * Australian HCI Conference

General

 * Ronald M. Baecker, Jonathan Grudin, William A. S. Buxton, Saul Greenberg (1995): Readings in human-computer interaction. Toward the Year 2000. 2. ed. Morgan Kaufmann, San Francisco 1995 ISBN 1-558-60246-1
 * William S. Bainbridge, ed. (2004): Berkshire Encyclopedia of Human-Computer Interaction. 2 volumes. Great Barrington, MA: Berkshire. http://www.berkshirehci.com. ISBN 0-9743091-2-5
 * Stuart K. Card, Thomas P. Moran, Allen Newell: The Psychology of Human-Computer Interaction. Erlbaum, Hillsdale 1983 ISBN 0-89859-243-7
 * Alan Dix, Janet Finlay, Gregory D. Abowd, and Russell Beale (2003): Human-Computer Interaction. 3rd Edition. Prentice Hall, 2003.  http://hcibook.com/e3/  ISBN 0-13046-109-1
 * Brad A. Myers: A brief history of human-computer interaction technology. Interactions 5(2):44-54, 1998, ISSN 1072-5520 ACM Press. http://doi.acm.org/10.1145/274430.274436
 * Jakob Nielsen: Usability Engineering. Academic Press, Boston 1993 ISBN 0-12-518405-0
 * Donald A. Norman: The Psychology of Everyday Things. Basic Books, New York 1988 ISBN 0-465-06709-3
 * Jef Raskin: The humane interface. New directions for designing interactive systems. Addison-Wesley, Boston 2000 ISBN 0-201-37937-6
 * Ben Shneiderman: Designing the User Interface. Strategies for Effective Human-Computer Interaction. 3. ed. Addison Wesley Longman, Reading 1998 ISBN 0-201-69497-2
 * Bruce Tognazzini: Tog on Interface. Addison-Wesley, Reading 1991 ISBN 0-201-60842-1
 * Julie A. Jacko and Andrew Sears (Eds.). (2003). Handbook for Human Computer Interaction. Mahwah: Lawrence Erlbaum & Associates. ISBN 0-8058-4468-6