This paper offers a novel methodological perspective to public diplomacy studies discussing how to apply Qualitative Longitudinal Research (QLR) into public diplomacy. Accordingly, the paper first discusses the existing academic literature on longitudinal research in social sciences and highlights the necessity to use QLR in public diplomacy studies. Second, it offers a research design on how to conduct QLR in public diplomacy. Third, the paper discusses the historical evolution of German public diplomacy over a period of 70 years as viable case study comparing three global sports events, namely the 1936 Berlin Olympics, the 1972 Munich Olympics and the 2006 World Cup. Overall, the paper argues that QLR has an important potential to advance public diplomacy studies since it enables researcher to trace continuity and change in public engagement policies over extended periods and explain whether historical legacies are reproduced or erased over time and how this resonates with international audience.

本文为公共外交研究提供了一个新的方法论视角，讨论如何将定性纵向研究 (QLR) 应用于公共外交。因此，本文首先讨论了关于社会科学纵向研究的现有学术文献，并强调了在公共外交研究中使用 QLR 的必要性。其次，它提供了如何在公共外交中进行 QLR 的研究设计。第三，本文讨论了德国公共外交 70 年来的历史演变，作为比较三个全球体育赛事（即 1936 年柏林奥运会、1972 年慕尼黑奥运会和 2006 年世界杯）的可行案例研究。全面的，