摘要：Models or diagrams of concepts are important to many types of research. As Stryker (1980) has so aptly noted, "Humans resp.and not to the o.atiYe world, but to the world as categorized or classified; the physical, biological, and social environment in which they Ttve is a symbolic environment.l The symbols that attach to the environment have meaning, are cues to behaviorr, and organize behavior" (Stryker 1980). For years, people have used models and diagrams to more easily convey complex ideas and information. More recently, there has been increasing interest in the use of models to describe various environmental impacts, and, even more recently, to aid decision analysis.
