Combining Text and Visuals for Effective Data Communication

Although information visualizations are widely used to communicate data-driven insights, the role of text in these visualizations remains understudied. Titles, captions, annotations, and other text components are pervasive and influential in real-world visualization designs. Despite the prevalence of text, the visualization field has limited empirical evidence, theoretical structure, and design guidance for understanding how text and visual elements work together. This dissertation addresses these gaps by investigating the role of text in visualization from both reader and designer perspectives. The first part of the dissertation presents three empirical studies examining how text shapes reader experience and interpretation. These studies show that readers prefer text-rich visualizations and that text influences some interpretations (e.g., takeaways and perceptions of bias) but not others (e.g., predictions). The second part investigates how visualization designers use and reason about text. Through analyses of published visualizations and interviews with practitioners, this work identifies and examines ten functions of text, four recurring design patterns, and six common challenges designers face when adding text, and the value of writing as a steering mechanism to clarify goals and audience needs within the design process. Together, these findings challenge assumptions favoring minimalist visual designs and demonstrate that text is a multifaceted and critical feature of visualizations. These contributions deepen our understanding of visualization as a multimodal communication form and lay the groundwork for future research, empirical guidelines, and design tools that more fully integrate text and visualization.