Radar Display

Configural displays were the inspiration for the radar display. Configural displays arrange variables in both space and format so that a property of this configuration emerges to signal a significant, task-relevant, integrated variable (Wickens, Lee, Liu, & Becker, 2004; Hansen, 1995). This property is defined as an emergent feature (Pomerantz, 1986; Pomerantz & Pristach, 1989; Sanderson, Flach, Buttigieg, & Casey, 1989). According to Pomerantz (1986), these figures can be perceived faster in divided-attention tasks in which all parts have to be taken into account than figures without emergent features.

Due to limited project time, only one type of display could be implemented and tested. The radar display was chosen due to its unique form and efficient use of screen space. Variables of interest are placed as points on intersecting lines. All of the points are connected to form a shape, which is the emergent feature of the display. There are also two methods in which a radar display can be constructed—absolute and relative—both with their benefits and costs.

Absolute Radar Display

For the absolute radar display, the lines on which the points lie will be scaled from the minimum and maximum possible amounts for each point. When the operator changes the SP of a variable, its corresponding point will move along its line. This causes the shape at which everything is within normal range – the ideal shape - to change, requiring the operator to constantly update his/her memory of the ideal shape. The SP point on the line moves along the line in a pattern that is compatible with the change in SP values made by the operator. This supports the expected relationship between the SP points on the radar display and the SP values that are entered in by the operator (Roscoe, 1968; Fitts & Seeger, 1953). It also provides supportive feedback of what the operator has done and makes the system status visible (Nielsen, 1994).

Relative Radar Display

For the relative radar display, the point representing the SP never moves, even when the operator changes its value, keeping a consistent ideal shape is displayed at all times. The PV points move in respect to the SP points.