APPENDIX 1: Definitions
Alarm: An alarm announces by audible means, or audible and visual means, a condition of an abnormal situation requiring attention.
Alphanumerics: Characters presented on a visual display as letters, numbers, digits, and usually other characters, such as punctuation marks or combinations of them.
Ambient Light: Light originating from sources other than the operator's visual displays, i.e., the general level of illumination on the bridge due to sunlight or lights and lamps.
Ambient Noise: All of the background sounds in the work environment, e.g., the general level of background noise on the shipbridge.
Brightness: An attribute of visual sensation that is determined by the intensity of light radiation reaching the eye. Along with hue and saturation, a component of perceived color.
Character: A letter, digit, or other symbol that is used as part of the organization, control, or representation of data. A character is often in the form of a spatial arrangement of adjacent or connected strokes.
Character Size: Measured by the height of a displayed character in terms of its visual angle.
Coding: Use of a system of symbols, shapes, colors, or other variable sensory stimuli to represent specific information.
Console: The structural framework for the integration of devices, equipment, and storage and which together compromise a workstation.
Contrast: The difference in luminance between foreground objects and their background or, generally, between any two areas of a display, measured with the contrast ratio (division of the luminance of the foreground by the luminance of the background).
Control: A mechanism used to regulate or guide the operation of a machine, equipment component, subsystem, or system.
Cursor: A highlighted, moveable indicator on the computer screen that shows the current location for data entry, editing, or selection of a displayed object.
Display (Visual): Means which presents visual information, including conventional instrumentation.
Display Field: An area of the display screen reserved for the display of information.
Effective Temperature: An index which combines into a single value the effect of temperature, humidity, and air movement on the sensation of warmth or cold felt by the human body. The numerical value is that of the temperature of still, saturated air which would induce an identical sensation.
Ergonomics: The study and design of working environments (e.g., workstation, cockpit, ship bridges) and their components, work practices, and work procedures for the benefit of the worker's productivity, health, comfort, and safety. Application of the human factor in the analysis and design of equipment, work and working environment.
Field of Vision: Angular size of a scene that can be observed from a position on the ship's bridge.
