The increasing demand for group support in software has drawn more attention to the field of designing Group Support Systems. Notwithstanding all the research in this field the process of designing Group Support Systems is still complex due to the involvement of many different stakeholders and the diversity in applications. In order to contribute to the complex process of designing Group Support Systems we have composed an evaluation framework for the requirements analysis and elicitation phase of the design process. This framework combines two perspectives on different levels: a pragmatic one measuring general performance in practice and a theoretical one based on fundamental Computer Supported Co-operative Work concepts. KEYWORDS Group Support Systems , CSCW, Design, Concepts, Requirements