Human-computer interaction

Human-computer interaction (HCI) is the field of research and design concerned with how people use computing systems and with the interfaces between people and computers. A widely cited definition from the 1992 ACM SIGCHI curriculum report describes it as "a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them." The field draws on computer science, cognitive and behavioral psychology, design, human factors engineering, and several other disciplines.

The term was popularized by Stuart Card, Thomas P. Moran, and Allen Newell in their 1983 book The Psychology of Human-Computer Interaction, which set out to give an applied psychology of interactive computing a scientific footing. Virtual reality (VR) and augmented reality (AR) are among the field's research areas, because head-worn displays and three-dimensional input move interaction off the flat screen and into space, where established two-dimensional interface conventions do not directly apply.

Scope and disciplines

HCI sits at the intersection of computer science and the human and design sciences. The 1992 SIGCHI report places it among computer science, cognitive psychology, social and organizational psychology, ergonomics and human factors, linguistics, philosophy, sociology, and graphic and industrial design. The work spans the design of interaction techniques and interfaces, empirical evaluation of how well people perform with them, and theory about perception, attention, memory, and motor control as they bear on using machines.

The Card, Moran, and Newell book introduced cognitive engineering models that remain part of HCI teaching, including the Model Human Processor, which treats the human as an information-processing system with perceptual, cognitive, and motor subsystems, and the GOMS family of models (Goals, Operators, Methods, and Selection rules) for predicting how long a skilled user takes to complete a task. Card and Moran's earlier Keystroke-Level Model, a simplified form of GOMS, was first proposed in 1980 and presented in the same book.

Origins

A precursor to immersive HCI is Ivan Sutherland's 1965 essay "The Ultimate Display," which described a display not as a surface for showing information but as a window into a computer-controlled world that could look, sound, and feel real. Sutherland wrote that "a display connected to a digital computer gives us a chance to gain familiarity with concepts not realizable in the physical world. It is a looking glass into a mathematical wonderland." Ivan Sutherland went on to build an early head-mounted display in the late 1960s, work that later writers treat as a root of both interactive computer graphics and VR.

HCI took shape as an organized field in the early 1980s. The applied-psychology group that produced the Card, Moran, and Newell work had formed at Xerox PARC in 1974. In 1982 the ACM Special Interest Group on Computer-Human Interaction (SIGCHI) was created by renaming and refocusing the earlier Special Interest Group on Social and Behavioral Computing, and its formation was announced at the Human Factors in Computer Systems conference in Gaithersburg, Maryland, organized by Bill Curtis and Ben Shneiderman. The first ACM Conference on Human Factors in Computing Systems (CHI) was held in Boston in 1983, and CHI has since become the field's flagship annual conference; the 2026 edition was held in Barcelona.

Relevance to virtual and augmented reality

In a desktop interface the user works through a small set of devices, a keyboard and a pointing device, acting on a two-dimensional screen. Virtual reality and augmented reality remove that frame: output is presented on a stereoscopic head-mounted display and input can come from the position and orientation of the head and hands, from the eyes, and from speech. The study of these interfaces is treated as a distinct subfield, three-dimensional user interfaces, defined by Doug Bowman, Joseph LaViola, Ernst Kruijff, Ivan Poupyrev, and Ryan McMahan as user interfaces involving interaction in three spatial dimensions. Their textbook organizes the area around the canonical spatial tasks of selection, manipulation, navigation, and system control, and covers visual, auditory, and haptic output together with three-dimensional input devices.

Interaction techniques for selection and manipulation

A recurring HCI problem in VR is letting a user select and move objects that are out of physical reach. The Go-Go interaction technique, presented by Ivan Poupyrev, Mark Billinghurst, Suzanne Weghorst, and Tadao Ichikawa at the 1996 ACM Symposium on User Interface Software and Technology, addresses this with a non-linear mapping between the physical hand and the virtual hand: while the hand stays near the body the mapping is one-to-one, but once it passes about two thirds of the user's arm length the virtual hand extends much further, as if the arm were growing. An alternative class of techniques uses ray-casting, in which a ray emanates from the virtual hand and the user selects whatever object the ray intersects. Doug Bowman and Larry Hodges compared arm-extension and ray-casting techniques in a 1997 study and found ray-casting faster for selecting remote objects, though arm-extension methods such as Go-Go support more direct positioning once an object is grabbed.

Multimodal input: gaze, gesture, and voice

Current VR and AR headsets combine several natural input channels rather than a single device. Eye tracking supports gaze-based pointing, hand tracking supports gesture and pinch input, and speech recognition supports voice commands; systems often fuse two or three of these so that, for example, the user looks at a target, says a command to confirm it, and uses a hand gesture to adjust a value. Each modality has trade-offs studied in the HCI literature: hand gestures must contend with occlusion and can cause arm fatigue over long sessions, while voice adds a complementary channel that does not require the hands. Designing and evaluating these combinations, and the spatial audio and haptics cues that accompany them, is an active part of HCI research on spatial computing.

Presence and embodiment

Beyond input and output, HCI research on VR and AR examines subjective responses to immersive systems, including presence, the sense of being in the virtual place rather than in the physical room, and embodiment, the sense that a virtual body belongs to the user. These constructs are treated as evaluation criteria for immersive interfaces alongside conventional usability measures, and they shape how interaction techniques and avatars are designed.