ABSTRACT
The construction of alternative future scenarios is often an early task within an impact assessment (IA) project. The time horizon of major IA projects has become rather distant. There are general agreements among IA practitioners as to the kind of components which a comprehensive IA project should comprise. The ultimate objective of the IA projects is to aid policy making by the government agency. The agency has the authority to make certain policies that will have a great deal of influence in certain technological and socioeconomic areas, but very little in other areas. The embedding framework implies that the results of practically all the tasks within an IA project would be dependent functions of the alternative scenarios. The embedding of any IA task in a scenario implies that the scenario will specify either some exogenous variables or some basic premises, or both, which are needed for that task to be carried out.
