As online news increasingly include data journalism, there is a corresponding increase in the incorporation of visualization in article thumbnail images. However, little research exists on the design rationale for visualization thumbnails, such as resizing, cropping, simplifying, and embellishing charts that appear within the body of the associated article. Therefore, in this paper we aim to understand these design choices and determine what makes a visualization thumbnail inviting and interpretable. To this end, we first survey visualization thumbnails collected online and discuss visualization thumbnail practices with data journalists and news graphics designers. Based on the survey and discussion results, we then define a design space for visualization thumbnails and conduct a user study with four types of visualization thumbnails derived from the design space. The study results indicate that different chart components play different roles in attracting reader attention and enhancing reader understandability of the visualization thumbnails. We also find various thumbnail design strategies for effectively combining the charts' components, such as a data summary with highlights and data labels, and a visual legend with text labels and Human Recognizable Objects (HROs), into thumbnails. Ultimately, we distill our findings into design implications that allow effective visualization thumbnail designs for data-rich news articles. Our work can thus be seen as a first step toward providing structured guidance on how to design compelling thumbnails for data stories.

翻译：随着在线新闻越来越多地包含数据新闻，文章缩略图中融入可视化的做法也相应增加。然而，目前关于可视化缩略图设计原理的研究尚显不足，例如对关联文章正文中出现的图表进行缩放、裁剪、简化和修饰的策略。因此，本文旨在理解这些设计选择，并确定何种因素能使可视化缩略图兼具吸引力与可解释性。为此，我们首先调研了在线收集的可视化缩略图，并与数据记者和新闻图形设计师探讨了可视化缩略图的实践。基于调研与讨论结果，我们定义了可视化缩略图的设计空间，并开展了一项用户研究，涉及该设计空间衍生的四类可视化缩略图。研究结果表明，不同的图表组件在吸引读者注意力与增强读者对可视化缩略图理解性方面发挥着不同作用。我们还发现多种有效的缩略图设计策略，用于将图表组件（例如带高亮与数据标签的数据摘要、带文本标签与人可识别对象（HROs）的图例）有效整合为缩略图。最终，我们将研究发现凝练为设计启示，为面向数据丰富新闻文章的有效可视化缩略图设计提供支持。因此，我们的工作可视为迈向为数据故事设计引人入胜的缩略图提供结构化指导的第一步。