In environmental studies the word design is often used in a broad sense encompassing the full range of activities undertaken and schedules followed during the course of a particular project. In effect, design has been taken to mean “course of action.” In this review a definition more associated with basic research will be employed. Design is the plan by which a goal will be achieved and includes an unambiguous statement of that goal, a sampling scheme for the collection of appropriate data and an objective method of drawing conclusions from the examination of those data. When reviewing designs, we are most greatly concerned with the connection between original purpose and final conclusion.