The trends in the macro environment of organizations coupled with advances in information technology have created opportunities for organizations to increase their effectiveness. If managed appropriately, these trends and advances can increase the strategic advantage to the organization. This requires a perspective on the organization and its use of information technology which incorporates social-organizational as well as technical-economic aspects of information technology use. However, the traditional narrow techno-economic focus of system designers and information systems development methodologies, and the consequent neglect of socio-organizational aspects of the systems, has resulted in only a limited increase in organizational effectiveness. Furthermore, in many instances, this has led to a deterioration' of the organizational climate and quality of working life within it, thereby causing systems problems and implementation failures. There is, therefore, a need for an information systems development paradigm and associated methodologies which jointly consider both the social-organizational and the techno-economic aspects of information systems. The socio-technical systems (STS) approach to systems development is one such approach. This paper describes the principles, assumptions, and the development process of the socio-technical systems approach. It then goes on to analyze and compare three socio-technical methodologies (Mumford 1983a; Pava 1983b; and Bostrom and Heinen 1977b) available in the information systems literature. The analysis and comparison of the methodologies indicates that no one methodology is complete and comprehensive in all aspects of STS development. This points to the need for mixing and matching various components of different methodologies and augmenting them where necessary.