Considerable attention has been given to the role of Strategic Environmental Assessment (SEA) in policy, plan and program (PPP) assessment; however, there is still very little consensus on appropriate methodologies for SEA. Despite calls for SEA to develop more independently of project-level assessment, existing SEA methodologies still tend to be based on project-level EIA principles, rather than also on a trickling down of objectives of broader environmental policy. This thesis argues that if SEA is to advance in application and effectiveness then a different, but structured methodological framework is required. -- While SEA can perhaps utilize many of the existing methods and techniques from project- level assessment, the types of questions being addressed in strategic assessment are inherently different from those in project-level assessment. Accordingly, a different methodological assessment framework is required for SEA. The emphasis of strategic assessment is on the development of an appropriate strategy for action, addressing alternative courses of action, rather than the assessment of the potential impacts of a pre-determined option. In order to accomplish this, SEA methodology must be more broad brush than project-level assessment in order to allow the assessment of both the more general policy issues and the more technical plan and program issues. Similar to project-level assessment, however, a structured framework is desired in order to facilitate a more systematic and replicable assessment process. -- This thesis develops a structured, generic seven-phase assessment framework to guide SEA application. The framework is demonstrated through a case study SEA of potential Canadian energy policy alternatives. Through the use of a modified policy-type Delphi and multi-criteria analytical methods, alternative options for Canadian energy policy are evaluated and the 'best practicable environmental option' is determined. While the geographic scale of the case study and the number of participants involved is perhaps not pragmatic with respect to 'real-world' policy SEA, it does serve to demonstrate the utility of the proposed SEA framework. The emphasis of this research is on the process of strategic assessment, rather than the policy implications of the results of the case study. A number of specific recommendations for 'good-practice' SEA are presented, and key issues are raised for future SEA research.