User Performance Under Several Automated Approaches to Changing Displayed Maps

Performance in a route selection task was used to evaluate automated methods for changing from one displayed segment of a map to another. Participants were 24 Army officers, who chose successive 675000000000. km map segments (1:50,000 scale) for solving 12 problems. Each problem requested the fastest road route between pairs of cities within a 60 x 81 km region. Participants solved problems by electronically marking road routes across map segments. Methods for changing map segments were (a) continuous map scanning and (b) discrete map segments using three different amounts of border overlap (0%, 25%, and 50%). Results showed that different map change conditions did not significantly affect the quality of routes chosen. The least time for problem solutions occurred when map segments with 50% overlap were used, although 25% overlap produced similar data. Designers of map display systems for the military could optimize user performance time with discrete map segments that overlap by about 25%.