User Interface Techniques - Interaction Tasks and Domain Objects

Interaction Tasks and Domain Objects

An interaction task is "the unit of an entry of information by the user", such as entering a piece of text, issuing a command, or specifying a 2D position. A similar concept is that of domain object, which is a piece of application data that can be manipulated by the user.

Interaction techniques are the glue between physical I/O devices and interaction tasks or domain objects. Different types of interaction techniques can be used to map a specific device to a specific domain object. For example, different gesture alphabets exist for pen-based text input.

In general, the less compatible the device is with the domain object, the more complex the interaction technique. For example, using a mouse to specify a 2D point involves a trivial interaction technique, whereas using a mouse to rotate a 3D object requires more creativity to design the technique and more lines of code to implement it.

A current trend is to avoid complex interaction techniques by matching physical devices with the task as close as possible, such as exemplified by the field of tangible computing. But this is not always a feasible solution. Furthermore, device/task incompatibilities are unavoidable in computer accessibility, where a single switch can be used to control the whole computer environment.