Social media systems are as varied as they are pervasive. They have been almost universally adopted for a broad range of purposes including work, entertainment, activism, and decision making. As a result, they have also diversified, with many distinct designs differing in content type, organization, delivery mechanism, access control, and many other dimensions. In this work, we aim to characterize and then distill a concise design space of social media systems that can help us understand similarities and differences, recognize potential consequences of design choices, and identify spaces for innovation. Our model, which we call Form-From, characterizes social media based on (1) the form of the content, either threaded or flat, and (2) from where or from whom one might receive content, ranging from spaces to networks to the commons. We derive Form-From inductively from a larger set of 62 dimensions organized into 10 categories. To demonstrate the utility of our model, we trace the history of social media systems as they traverse the Form-From space over time, and we identify common design patterns within cells of the model.

翻译：社交媒体系统既多样化又无处不在。它们已被广泛用于工作、娱乐、行动主义与决策制定等多种场景。正因如此，社交媒体系统也呈现出多元化的特征，不同系统在内容类型、组织方式、分发机制、访问控制等诸多维度上存在显著差异。本研究旨在对社交媒体系统进行表征，进而提炼出一个简洁的设计空间，以帮助我们理解系统间的异同，认识设计选择可能带来的影响，并识别创新空间。我们提出的模型命名为Form-From，该模型基于以下两个维度对社交媒体进行刻画：(1) 内容的形式，分为线程式（threaded）与扁平式（flat）；(2) 内容接收的来源，涵盖空间（spaces）、网络（networks）到公共资源（commons）。Form-From模型是通过对涵盖10个类别、共62个维度的更大维度集进行归纳推导而构建的。为展示该模型的实用性，我们追溯了社交媒体系统随时间在Form-From空间中的演化轨迹，并识别了模型各单元内的常见设计模式。