We experience the world around us in two ways. By direct experience of living in, travelling through or manipulating our environment, and most of the chapters in this book are concerned with children's and adolescents' direct experience of their environments. But we also learn about the world through secondary sources – for example from spatial representations like maps, from written descriptions, such as guide books, and from visual images like films. These are particularly important sources of knowledge for environments that we have not had the opportunity to experience directly. Compared to the research into children's direct experience and activity in their local environments, there is little research into how children learn about places from secondary sources, and even less into how children combine information from experience and from secondary sources.

In this chapter we will discuss how young children understand one secondary source of information – aerial photographs. In particular we will consider how children relate aerial photographs to real places, in other words how they use photographs to interpret the immediate environment. And we will also consider the reverse issue – what types of environmental experience contribute to children's ability to interpret aerial photographs.

Understanding spatial representations, such as maps, models, and map-like photographs, has at least two functions, for children and adults alike. First, such representations can serve as compact, durable and portable representations of large areas of the world.

In this book, you are about to meet people who are passionate about environments for children. The environments of children are not always environments for children: in many cases, the places where children grow up, play, and learn are, at best, designed for them by adults, at worst they are the spaces left over from the ‘adult world’. So it is not surprising that many researchers in this area do not remain neutral, but instead take an involved, action-orientated stance in their work.

Environmental psychology has indeed become one of the least neutral areas of the discipline of psychology, striving to work for better environments, working to discover the correlates of well-being, arming designers with the information that they need about people's needs and perceptions, and providing the tools for evaluating places and buildings as they affect behaviour and well-being.

Theories and applications

We have asked the author of each chapter to review theories of children's perceptions of space and place, and to show applications to the world of children. So, for example, Edward Cornell and Kenneth Hill apply the literature about children's developing ideas of themselves in geographical space to predict what children are most likely to do if they find themselves lost in the outdoors. This is research that has immediate practical importance for advising police search teams on how far a child is likely to have wandered.