Based on a review of economists' debates on mathematical economics, this article discusses a key issue for shaping the science of social work--research methodology. The article describes three important tasks quantitative researchers need to fulfill in order to enhance the scientific rigor of social work research. First, to test theories using empirical data, researchers should follow the positivistic/postpositivistic principles. Second, social work researchers should incorporate the latest advances in methods from other disciplines. Third, researchers should use quantitative methods to address the most pressing and challenging issues of social work research and practice.