showing depth and two horizontal dimensions. It could be a geological cross section in which time replaces depth as the vertical axis. Instead of an immersive space, the representation of the building could be a plan and elevation, an architect’s three-dimensional physical model, or an ordered series of architectural renderings, viewing the interior from different places in the building with a near-photographic appearance. Representations can capture what is (e.g., a map of a city), what might be (e.g., a sketch of an addition to a house on a lunchroom napkin), and what should be (e.g., a score for a piece of music or dance).
Reasoning processes can ask: What happens if we add weight to one part of the pulley system, if we remove weight from another part, or if the string breaks in a particular place? We can ask which parts move, how far, and what the equilibrium position is. In the other cases, we can ask how the thickness of the rock layers varies with depth, or what the “sense” of space is that we “feel” as we move through the lobby of the building. The questions can capture either the results of change or the process of change. They can deal with possible or hypothetical (“what would it look like if”) situations (e.g., a fly’s-eye view of the atrium of the building or David Macaulay’s images of parts of the urban infrastructure “floating” in three-dimensional space without the surrounding and supporting physical ground) (Figure 2.2).
Spatial thinking occurs in private and in public. On the one hand, spatial thinking encompasses a range of cognitive processes that support exploration and discovery: we can visualize relations, imagine transformations from one scale to another, rotate an object to look at its other sides, create novel viewing angles or perspectives, evoke images of places and spaces, and so forth (see Hanson and Hanson, 1993). On the other hand, spatial thinking allows us to externalize these operations by creating spatial representations in a range of media, forms, and sensory modalities: tactile maps or graphs, auditory maps, vibrotactile surfaces, traditional cartographic maps, two-dimensional graphs, link or flow diagrams, tree diagrams of hierarchical relations, three-dimensional (3-D) scale models, exploded views of a structure, and so on. The representations can be created as part of a personal working dialogue. They can be shared with others, thus exposing the representational and reasoning processes of spatial thinking to public scrutiny. The representations are simultaneously ways of expressing personal understanding and rhetorical acts of communication and persuasion that can establish a public consensus.
Crucial to the power of spatial thinking is our ability to use space as a framework for understanding. The process of interpretation begins with data:
Data consists of numbers, text, or symbols which are in some sense neutral and almost context-free. Raw geographic facts, such as the temperature at a specific time and location, are examples of data. When data are transmitted, they are treated as a stream of bits; and the internal meaning of the data is irrelevant to the transfer process.
Information is differentiated from data by implying some degree of selection, organization, and preparation for a particular purpose—information is data serving some purpose, or data that have been given some interpretation. (Longley et al., 2001, p. 6)
There are three spatial contexts within which we can make the data-to-information transition: those of life spaces, physical spaces, and intellectual spaces. In each case, space provides the essential interpretive context that gives meaning to the data.