論文アブストラクト：All too often, research partnerships are project-driven and short-lived. Multi-lifespan design and other longer-term approaches offer alternative models. In this paper, we contribute one alternative model for cross-boundary research partnerships spanning longer timeframes and offer one best practice: collaborative reflection. Specifically, we provide an in-depth case study of a multi-lifespan design partnership (over nine years and ongoing) between a Rwandan NGO focused on peacebuilding and a US university research group focused on information design theory and method. First, we document our process for conducting a collaborative reflection that seeks balance among the contributors while navigating differences in culture, discipline, experience, and skills. Next, we reflect on five themes: (1) common ground: sensibilities and commitments; (2) trust; (3) research landscape: crossing nations and institutions; (4) research as a healing mechanism; and (5) multi-lifespan design partnership. We conclude with a discussion of overarching considerations for design researchers who engage in cross-boundary research partnership.