This paper makes the case for the application of the dual methodology in the IS field. Leonard-Barton (1988) has initially used this design to investigate innovation processes. A research project devoted to organizational impacts of intranet practices provides an illustration of the appeal of the method in our discipline. The dual methodology combines multiple - retrospective – broad case studies and a single – processual – fine-grained one. Its advantages come from the combination of the two kinds of cases whose strengths and weaknesses mutually compensate. They also derive from synergies between multiple and single cases which are valuable to build a dialog between empirical evidence and literature review. The dual methodology seems especially suitable to address three core challenges of the IS field. First, it provides both broad and deep observations. Second, it helps students to reintroduce ITs and organizations in their investigations. Researchers take in consideration the specificities of technological artifacts under scrutiny while not overlooking central aspects of collective action. Third, rigor and relevance may be balanced. Criteria of rigor may be achieved thanks to the two kinds of cases. Simultaneously, the method requires frequent access to diverse fields. Constant back-and-forth between data collection and analysis and numerous reports to academic as well as managerial audiences prove invaluable to establish rigorous and relevant findings.