Comparing perceptual judgment and subjective measures of spatial awareness.

Spatial awareness is important in domains where safety hinges on human operators keeping track of the relative locations of objects in the environment. While a variety of subjective and judgment-based measures have been used to evaluate spatial awareness, none have probed all three of its levels: (1) identification of environmental objects, (2) their current locations relative to the operator, and (3) their relative positions over time. This work compares new judgment-based measures of spatial awareness that probe all three levels of spatial awareness to conventional subjective measures. In the evaluation of 14 configurations of Synthetic Vision Systems head down displays (seven terrain textures and two Geometric Fields of View (GFOVs)), 18 pilots made four types of judgments (relative angle, distance, height, and abeam time) regarding the location of terrain points displayed in 112 5-s, non-interactive simulations. They also provided subjective demand, awareness, clutter, SA-SWORD, and preferred GFOV measures. Correlation analyses revealed that displays that received higher awareness and SA-SWORD subjective ratings were associated with smaller errors in abeam time judgments and, for SA-SWORD, smaller errors in relative distance judgments. Thus SA-SWORD provides insight into level 2 spatial awareness and both SA-SWORD and awareness provide insight into level 3 spatial awareness. ANOVA and chi(2) analyses revealed comparable results between display configurations that produced the minimum error in judgments and those recommended by the awareness, SA-SWORD, and preferred GFOV measures.