The methods and procedures governing the way that information is exchanged between the user and the computer system. It involves the consistent formatting of prompts, check boxes, lists of options, sliders, messages, and other constructs. There are modal dialogues, where the user can do nothing else until the action required to satisfy the dialogue has been taken; this can be as simple as acknowledging a message. Conversely, a modeless dialogue is one that may be returned to after attending to other matters. See also dialogue box.