We present a systematic review and design space for visualizations on smartwatches and the context in which these visualizations are displayed--smartwatch faces. A smartwatch face is the main smartwatch screen that wearers see when checking the time. Smartwatch faces are small data dashboards that present a variety of data to wearers in a compact form. Yet, the usage context and form factor of smartwatch faces pose unique design challenges for visualization. In this paper, we present an in-depth review and analysis of visualization designs for popular premium smartwatch faces based on their design styles, amount and types of data, as well as visualization styles and encodings they included. From our analysis we derive a design space to provide an overview of the important considerations for new data displays for smartwatch faces and other small displays. Our design space can also serve as inspiration for design choices and grounding of empirical work on smartwatch visualization design. We end with a research agenda that points to open opportunities in this nascent research direction. Supplementary material is available at: https://osf.io/nwy2r/.

翻译：本文系统综述了智能手表及其显示情境——智能手表表盘上的可视化设计，并构建了对应的设计空间。智能手表表盘是佩戴者查看时间时所见的主要屏幕，它以紧凑形式呈现多种数据的微型仪表盘。然而，智能手表表盘的使用情境与形态因素为可视化设计带来了独特挑战。我们针对主流高端智能手表表盘，基于其设计风格、数据数量与类型、可视化风格与编码方式，进行了深入的回顾与分析。通过分析，我们推导出一个设计空间，为智能手表表盘及其他小型显示屏的新型数据展示提供重要设计考量全景视图。该设计空间还可启发设计选择，为智能手表可视化设计的实证研究提供理论基础。最后，我们提出研究议程，指出这一新兴研究方向中的开放性机遇。补充材料见：https://osf.io/nwy2r/。