This reference book sets out to provide a useful glossary to writers, reviewers and citizens interested in the EIS process. Over the last decade, environmental impact statements have developed a rich, but sometimes confusing vocabulary. The purpose of this book is to help people understand and communicate more effec­ tively by presenting, analyzing and comparing terminology used by various EIS organizations. This book is not a technical glossary or the standard glossary, but rather the first complete effort to assemble and examine the translation of complex technical EIS language into a vocabulary aimed directly at the lay reader. Two major factors are responsible for the confusion over EIS terminology: the diversity of professional vocabularies and multiple interpretations of federal regulations. Due to the di­ versity and breadth of professional jargons needed to describe the wide range of EIS subject matter, both quantitatively and qualita­ tively, EIS terminology has become a complex amalgam of profession­ al languages. The second factor of multiple interpretations of federal regulations contributes to the confusion over EIS procedur­ al terminology—providing a disjointed vocabulary charged with in­ dividual interpretation. As a ~esult of this complexity and con­ fusion, the need for a uniform or standard terminology has been advocated by many organizations, ranging from the Council on En­ vironmental Quality on the federal level, down to city planning departments on the local level.