Mode (user interface)

In Raskin's sense and according to his definition, an interface is not modal as long as the user is fully aware of its current state.

Larry Tesler defined modes as "a state of the user interface that lasts for a period of time, is not associated with any particular object, and has no role other than to place an interpretation on operator input.

"[3] Several examples of software have been described as modal or using interface modes: Larry Tesler at PARC devised insights for a modeless word processor from the feedback gathered from a user test with newly-hired Sylvia Adams, where she was asked to ad lib some gestures to correct proofreading marks on the digital text.

[5] This test convinced Tesler's manager Bill English of the problems with their previous modal interface.

Another typical problem is a sudden change of state that interrupts a user's activity, such as focus stealing.

Later he notes, " 'It is no accident that swearing is denoted by #&%!#$&,' writes my colleague, Dr. James Winter; it is 'what a typewriter used to do when you typed numbers when the Caps Lock was engaged'."

However, while such a method may reduce the risk of inadvertent wrong interactions, it does not solve the problem that the modal window blocks use of the application's normal features and so prevents the user from taking any action to fix the difficulty, or even from scrolling the screen to bring into view information which they need to correctly choose from the options the modal window presents, and it does nothing to alleviate the user's frustration at having blundered into a dead end from which they cannot escape without some more or less destructive consequence.

[24] HCI researcher Donald Norman argues that the best way to avoid mode errors, in addition to clear indications of state, is helping the users to construct an accurate mental model of the system which will allow them to predict the mode accurately.

Modal controls can be disruptive, so efforts should be made to reduce their capacity to block user work.

[26] The term quasimode is a composite of the Latin prefix quasi- (which means almost, to some degree) and the English word "mode".

The purported benefit of this technique is that the user does not have to remember the current state of the application when invoking a command: the same action will always produce the same perceived result.

In this case the increased possibility of a mode error is largely compensated for by the improved accessibility for users with physical disabilities.