Since the 1970s information system methodologies have proliferated rapidly, causing difficulties for those needing to select an appropriate methodology. This text provides a comparison study of methodologies by developing and using a conceptual framework. After discussing the wider information systems context and establishing and applying the framework to "ethics", "soft" and "structured" methodologies, the author presents four research case studies and discusses the lessons that these provide. The work concludes with recommendations and guidelines for practical use.