This article reviews conventional approaches to environmental policy evaluation, outlines their presumed relevance to policy making and implementation, and points out the main reasons why they have been subject to challenge. It contrasts the conventional approach to environmental policy evaluation—which presumes the identity of the policy analyst is unimportant—with the “collaborative approach,” which emphasizes the need to engage relevant stakeholders (i.e., the users of policy analyses and those affected by them) in the process of environmental policy evaluation. The article also describes the emergence of “adaptive” approaches to resource management and sustainable development, and explains why they represent an important shift away from emphasizing “success” and “failure” in environmental policy making and toward ongoing public learning for purposes of improvement.