What types of machine displays can give information to a human operator?

In human-factors engineering, a machine display is a signal that provides an operator with information regarding the condition or functioning of a system. These displays are designed to be perceived through various human senses to guide decision-making and action.12

Common types of machine displays include:

• Visual Displays: These are the most common form of output and include pointers on dials, flashing lights on control panels, and digital readouts. Modern systems utilize video display devices such as cathode-ray tubes and flat-panel displays, which can present alphanumeric, graphic, or video data.1
• Auditory Displays: These provide information through sound, such as warning buzzers or spoken commands issuing from a loudspeaker. These are particularly useful when an operator cannot divert their vision from a primary task.12
• Tactile Displays: These convey information through the sense of touch, such as the vibration of a game controller to provide feedback during operation.2

Designers may also explore other sensory interfaces, including olfactory (smell) and gustatory (taste) signals, to effectively communicate system status to the human operator.2