An Eye-Tracking Study on Sparklines within Textual Context

Abstract

Sparklines are placed in documents but their usability is rarely evaluated in their immediate context of paragraphs of text. We conducted an eye-tracking study to measure readability and understandability of four different conditions: two different sparkline chart types (bar and line charts) and two text languages (native and non-native languages). We found out that most participants out of 296 in total were not distracted by sparklines. Only 3.19% of the average reading time was spent looking at sparklines. There was no correlation between dwell time and data understanding, measured in a post-experiment quiz. The chart types did not have a significant effect on sparkline attention. However, compared with native textual context, sparklines in non-native text were more noticeable. The results of this study can be useful for future sparkline usage consideration.