A short term longitudinal study investigated the relationship between spatial activity and spatial competencies over the course of the preschool years. A group of 22 children, 3 years of age, were observed exploring two different novel environments with their mothers: an indoor children's museum and a small outdoor zoo. When the children were 3.5 to 4 years of age, they were given three tasks assessing ability to manipulate spatial knowledge of their preschool playground. Tasks assessed children's ability to use both near and distant landmarks, to infer spatial information not directly experienced, and to construct a toy model of the playground. Subjects were also given the Peabody Picture Vocabulary Test. One year later, 20 of the original 22 again received the assessment tasks, and teachers rated their attitudes toward exploring environments and materials. On the basis of initial observations, these preschool aged children were later classified as active or passive explorers. Overall, results indicated that: (1) passive and active explorers perform equally well on tasks assessing spatial competencies mastered earlier; (2) on tasks of moderate difficulty, passive explorers perform more poorly than active explorers but catch up later; and (3) on very difficult tasks, differences between active and passive explorers may be slight or nonexistent but may develop later. (RH)