Typologies are systems of classification. Each ecological perspective (environmental design, ecological design, social restoration, ecological restoration) is based on a broad philosophical position, world view. The work of the artists represented here is not necessarily limited to any of the four perspectives. For instance, it was a matter of interpretation to group Ann Hamilton's work, privation and excesses as a form of social restoration. Many of the artists do not necessarily associate themselves with the categories selected and some of their work addresses issues related to more than one typology. Similarly, the concept typologies are only separated as a way to help focus attention on a few of the many important environmental concepts used by contemporary ecological art. The concepts should not be viewed as mutually exclusive categories. Instead, the perspectives and concepts are identified as a way to help teachers identify and organize cross-disciplinary curriculum information and conduct action-oriented inquiry.