Designed to gain a more thorough understanding of the cognitive processes involved and apply this knowledge in defining improved teaching strategies, this study of contour interpretation (referred to as "position fixing") required 12 subjects to locate their position on a map after being transported, blindfolded, to test sites where terrain relief was the only topographic feature available for referencing. Six of the subjects, who were Marine Corps infantrymen with expertise in map interpretation, exhibited uniform problem-solving strategies, i.e., the use of large landforms (macrorelief) to reduce the size of the area of uncertainty. Six other Marine infantrymen with conventional training but limited experience, employed a different problem-solving strategy from that of the experts, and performed poorly. They focused only on microrelief, attempting to search the large area-of-uncertainty for the map portrayal of small terrain features. Results indicate that cognitive strategy training would increase the position-fixing skill of military map users who have completed a traditional course of instruction in map interpretation and that both expert and non-expert map users would benefit from contour line and landform visualization training. (LMM)