The design and development of Group Support Systems (GSS) is a complex endeavor. The long term usefulness of these systems can only be as good as their design. Sound design principles demand the adoption of a systematic methodology that matches the system design objectives. The focus of this paper is the use of Object-Orientation as a modeling technology for designing GSSs. We present a brief overview of popular Object-Oriented (OO) analysis and design methodologies, and argue in favor of a methodology that allows the description of phenomenon of interest in the form of role models [10] -an abstraction well suited to capturing the essence of collaborative work