This technical note explores the applications of usability testing to enhance the effectiveness of data visualizations in persuasive communication. It argues that beyond following best practices for visual design, usability testing-a common user research approach in website, app, and software development-can significantly improve how well data visualizations meet audience needs and accomplish persuasive goals. The note details various aspects of usability testing, including its objectives and methodologies applicable to charts versus interactive dashboards (e.g., five-second tests, task-based tests, and think-aloud protocols), and emphasizes iterative design based on feedback. By highlighting the importance of both qualitative and quantitative feedback from representative users, the document provides insights into creating more intuitive, efficient, and impactful data visualizations.
This case and data set can be used with data visualization software to tell a story with data through charts, maps, and dashboards. Using an independent wine shop, Market Street Wine, the case describes changes in customer demographics, tastes, purchasing methods, and other trends that prompted the owners to consider whether they should "extend the aisle" by expanding their wine selection. The COVID-19 pandemic and related supply chain issues presented new business challenges-but also opened new opportunities. Most notably, the difficulty obtaining traditional French and Italian labels, and the more easily available wines produced across the United States, which had the owners considering these offerings. Students can use the shop owner as audience and the wine consumer data to explore new wines, US regions, and trends to design charts, the narrative arc of a story to present, and a dashboard.