The interactive cycle can be divided into two major phases: execution and evaluation. Norman's model of interaction has seven stages: (1) establishing the goal; (2) forming the intention; (3) specifying the action sequence; (4) executing the action; (5) perceiving the system state; (6) interpreting the system state; (7) evaluating the system state with respect to the goals and intentions. The interaction framework attempts a more realistic description of interaction by including the system explicitly, and breaks into four main components. The nodes represent the four major components in an interactive system -- the System, the User, the Input and the Output. The interactive framework is presented as a means to judge the overall usability of an entire interactive system. All of the analysis that is suggested by the framework is dependent on the current task in which the User is engaged.
Ergonomics (or human factor) is traditionally the study of the physical characteristics of the interaction: how the controls are designed, the physical environment in which the interaction takes place, and the layout and physical qualities of the screen. A primary focus is on user performance and how the interface enhances or detracts from this. In the arrangement of controls and displays: Functional ones are organized so that those that are functionally related are placed together; Sequential ones are organized to reflect the order of their use in a typical interaction (important where particular task sequences are enforced, like aviation). Frequency controls and displays are organized according to how frequently they are used, with the most commonly used controls being the most easily accessible.
The physical environment of the interaction concerns questions like where the system will be used, who will used it and will users be standing or moving about? This may influence how well it is accepted and the health and safety of its users. Health issues include physical positions, temperature, lighting, noise, and time. Colours used in the display should be as distinct as possible, should not be affected by changes in contrast and should correspond to common conventions and user expectations.
Interaction can be seen as a dialog between the user and the computer. There are a number of common interface styles including: command line interface; menus; natural language; question/answer and query dialog; form-fills and spreadsheets; WIMP; point and click' three-dimensional interfaces. WIMP stands for windows, icons, menus and pointers (sometimes windows, icons, mice and pull-down menus), and is the default interface style for the majority of interactive computer systems, especially the PC and desktop workstation. 3D interfaces can making WIMP icons appear 3D, displaying flat objects in perspective when at an angle to the view and shrink when they are "further away" or in a virtual reality and information visualization system where the user can move about within a simulated 3D world.
Aesthetics and utility: remember that a pretty interface is not necessarily a good interface. The process of making software suitable for different language and cultures is called localization or internationalization. The presence of other people in a work environment affects the performance of the worker in any task. In the case of peers, competition increases performance (in known tasks). Similarly, the desire to impress superiors improves performance on these tasks. However when it comes to acquisition of new skills, the presence of these groups can inhibit performance. Consequently, privacy is important to allow users the opportunity to experiment. Interaction between the user and computer does not take place in a vacuum, but is affected by numerous social and organizational factors. These may be beyond the designer's control but awareness of them can help to limit any negative effects of the interaction.