Towards understanding how readers integrate charts and captions: A case study with line charts

Abstract

Charts often contain visually prominent features that draw atten-tion to aspects of the data and include text captions that emphasize aspects of the data. Through a crowdsourced study, we explore how readers gather takeaways when considering charts and captions to-gether.We frst ask participants to mark visually prominent regions in a set of line charts. We then generate text captions based on the prominent features and ask participants to report their takeaways after observing chart-caption pairs. We fnd that when both the chart and caption describe a high-prominence feature, readers treat the doubly emphasized high-prominence feature as the takeaway; when the caption describes a low-prominence chart feature, read-ers rely on the chart and report a higher-prominence feature as the takeaway. We also fnd that external information that provides context, helps further convey the caption's message to the reader. We use these fndings to provide guidelines for authoring efective chart-caption pairs.