This volume is a post-event proceedings volume and contains selected papers based on presentations given during a seminar, held in Dagstuhl Castle, Germany in September 2003. It was organized as a continuation of a series of workshops that have been co-located with larger conferences such as the International Conference on Software Engineering (ICSE) and the Conference on Object-Oriented Programming, Systems, Languages, and Applications (OOPSLA) since 2000. The 14 included papers were thoroughly peer-reviewed in two rounds of reviewing and are organized in topical sections on semantics for scenario-based notations, scenario-based notations in software validation and verification, analysis of scenario-based specifications, abstraction, refinement, and synthesis for scenario-based notations, non-functional properties and data in scenario notations, synthesis of executable models from scenario descriptions, tool support for scenario-based notations, domain and application specific dialects of scenario notations, scenario-based modelling patterns, integration of scenarios and implied behaviour.