Effects of Visual Variables on the Perception of Distance in Off-Screen Landmarks: Size, Color Value, and Crispness

Abstract

Maps on mobile devices provide the convenience of accessing spatial information of the surroundings. They also raise the concern that the small screen size impacts user’s acquisition of spatial knowledge as the small size causes the fragmentation of spatial knowledge. This fragmentation leads to the expense of more cognitive efforts and degradation of spatial knowledge. Following some effective approaches of representing distance to off-screen locations as contextual cues, this paper reports a design that incorporates not only the direction but also the distance using symbols. In addition, this study uses three different visual variables including size, color value, and crispness at the ordinal level of measurement and then compares their effectiveness on the perception of distance. Results show that color value contributes the least to the perception of distance. Size leads to slightly higher accuracy than crispness in comparing distances of off-screen landmarks. This study provides valuable information to further explore the impacts of different visual variables that could facilitate the acquisition of spatial knowledge on mobile devices. This study also points out the necessity of follow-up studies to clarify some issues in the current design as well as its impact on actual wayfinding performance.