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：本文对智能手表表盘上的可视化及其显示情境——即智能手表表盘——进行了系统性综述，并构建了设计空间。智能手表表盘是佩戴者查看时间时所见的主屏幕，这类表盘作为紧凑型数据仪表板，以简洁形式向佩戴者呈现多种信息。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。本文基于主流高端智能手表表盘的视觉风格、数据量与类型、可视化样式及编码方式，对其可视化设计进行了深入评述与分析。通过分析，我们提炼出一个设计空间，系统概述了智能手表表盘及其他小型显示屏在数据呈现方面需重点考量的要素。该设计空间既能激发设计灵感，也可为智能手表可视化设计的实证研究提供理论依据。最后，我们提出研究议程，指出这一新兴研究方向中的潜在机遇。补充材料详见：https://osf.io/nwy2r/。