APA Dictionary of Psychology

an entity produced by the interaction of small or simple elements (e.g., short line segments) in the visual system, such an entity (e.g., a polygon) being more salient to human perception than are the elements themselves. In ergonomics, object displays are usually designed to make use of emergent features; the display configurations yield an overall image (e.g., a rectangle or pentagon) that can be perceived holistically by the operator of a machine system and therefore rapidly analyzed to assess the state of the system. When a component of the system is not in the appropriate or normal state, the image will be distorted, alerting the operator to potential problems.