This dissertation develops a design framework for friendship-supportive youth social media. I conducted a qualitative meta-analysis across my formative, case-study, and co-design work with teens and young adults, synthesizing recurring design themes into three pillars: social understanding (legible norms, intentions, trust, reciprocity, and accountability), placeness (spatial and embodied affordances that make online interaction feel inhabitable), and identity alignment (authentic expression that remains current, plural, and interpretable). The framework is grounded in interpersonal, developmental, and sociotechnical theory, but its contribution is design-oriented: it translates broader accounts of friendship and social development into the specific ways social media platforms can shape youth friendship building. I initially validate parts of this framework through WhoamI Today (WIT), a platform deployed with 99 youth across the United States and Korea. My proposed work extends this validation through a follow-up deployment while refining the framework as a roadmap for cumulative design research on youth social media.

翻译：本论文提出了一个支持友谊构建的青少年社交媒体设计框架。通过对与青少年及年轻成人共同开展的形成性研究、案例研究和协同设计工作进行定性荟萃分析，我将反复出现的主题综合为三大支柱：社会理解（可辨识的规范、意图、信任、互惠和责任感）、场所感（使在线互动具有可居住性的空间性和具身性功能）以及身份对齐（保持当前性、多元性和可解释性的真实表达）。该框架以人际交往理论、发展理论和社会技术理论为基础，但其贡献以设计为导向：它将关于友谊和社会发展的广义论述转化为社交媒体平台塑造青少年友谊构建的具体方式。我通过"今日我是谁"（WhoamI Today, WIT）这一平台对该部分框架进行了初步验证——该平台在美国和韩国的99名青少年中部署。我拟定的工作将通过后续部署扩展这一验证，同时将该框架完善为青少年社交媒体累积性设计研究的路线图。