The AOS suggests 7 areas of examination:

General Ecology/General Environmental Science
Natural Resource Management
Environmental Chemistry
Statistics and Modeling
Environmental Management, Economics, and Policy
Environmental Technology and Physical Science
Pollution Ecology and Environmental Toxicity

Ph.D. students should be examined in 5 of these 7 areas, with General Ecology/General Environmental Science required to be one of the 5. In terms of exam format, we suggest that a five day written comprehensive exam be administered, followed by a 2-hour oral examination. These are only general guidelines and the student's advisory committee should have much input into the format. For example, individual committee members might specify whether their written questions are open or closed book.