Although Responsible Conduct of Research (RCR) training is common in the sciences, the effectiveness of RCR training is open to question. Three key factors appear to be particularly important in ensuring the effectiveness of ethics education programs: (1) educational efforts should be tied to day-to-day practices in the field, (2) educational efforts should provide strategies for working through the ethical problems people are likely to encounter in day-to-day practice, and (3) educational efforts should be embedded in a broader program of on-going career development efforts. This article discusses a complex qualitative approach to RCR training development, based on a sensemaking model, which strives to address the afore-mentioned training concerns. Ethnographic observations and prior RCR training served the purpose of collecting information specific to a multi-disciplinary and multi-university research center with the goal of identifying metacognitive reasoning strategies that would facilitate ethical decision-making. The extensive qualitative analyses resulted in the identification of nine metacognitive reasoning strategies on which future RCR training will be developed. The implications of the findings for RCR training in the sciences are discussed.