A monitor, or visual display is the portal that allows us to interact with the technology. A display (visual, auditory, tactile, etc.) is an artifact designed to support the perception of relevant system variable in order to help facilitate the processing of information. To create a user interface that creates a good experience for the user it is important to define the task that the interface is intended to support. A user must be able to process the information presented by the system. Engineering psychologist Christopher Wickens created thirteen principles divided into four categories.