This resource paper on spatial allocation analysis is part of a series designed to supplement undergraduate geography courses. Spatial allocation analysis is the study of the distribution of economic flows and transactions over geographical space. This account represents a general introduction to the process and its application in geographical inquiry. It proceeds by examining a series of models of spatial allocation systems, where the term "model" signifies an idealized representation. Under examination is a transportation problem model that includes (1) a set of geographically distinct points or regions which produce some commodity, (2) a set of geographically distinct points or regions which consume the same commodity, and (3) a given unit cost for transportation of the commodity from any producer to any consumer. In examining the flow of commodities, constraints are observed so that no supplier's total productive capacity is exceeded and all consumers' demands are met. Attention is focused first on the purely computational properties of the simple transportation model, then on the theoretical underpinnings of the model, and lastly on a variety of important, formal generalizations from the model. (Author/DE)