Visualization and Reporting
This chapter covers communicating findings visually. You will learn how to match chart types to the data and message, design effective dashboards and reports, and use KPIs and storytelling to make insight actionable.
Choosing the right chart
The chart should fit the question. Line charts show trends over time, bar charts compare categories, scatter plots reveal relationships between two continuous variables, histograms show the distribution of one continuous variable, and pie charts show parts of a whole at a single moment. Geographic maps, including choropleths that shade regions by value, reveal spatial patterns. Matching chart to message is the core skill of visualization.
Dashboards and reports
A dashboard presents key metrics at a glance for ongoing monitoring, while a report provides a more detailed, often periodic, narrative. Good dashboards focus on the KPIs the audience needs rather than crowding every available metric onto one screen, and they keep titles and labels clear. The goal is fast, accurate comprehension, not decoration.
KPIs and metrics
A key performance indicator (KPI) is a metric tied to a business objective, such as customer retention rate or on-time delivery percentage. Well-chosen KPIs are measurable, relevant to the audience, and comparable against a target or benchmark. Presenting a KPI alongside its target and trend gives viewers the context needed to act.
Design and storytelling
Effective visualization guides the viewer to the insight. Thoughtful use of color draws attention to what matters and encodes meaning consistently, while avoiding gratuitous effects that distract or mislead. Arranging visuals into a logical narrative, from context to finding to recommendation, helps audiences understand not just what the data shows but what they should do about it.