Data visualization is covered in Course 6 of the Google Data Analytics Certificate and is one of the most practically valuable topics in the entire program. This guide covers everything from choosing the right chart type to building effective dashboards in Tableau and telling data stories that actually influence decisions.
Choosing the Right Chart Type
One of the most common exam questions: given a dataset and an analytical goal, which chart type is most appropriate?
| Goal | Best Chart Type |
|---|---|
| Compare categories | Bar chart / Column chart |
| Show change over time | Line chart |
| Show distribution | Histogram / Box plot |
| Show part-to-whole | Pie chart / Donut chart (small number of segments) |
| Show correlation | Scatter plot |
| Compare multiple variables | Heatmap / Bubble chart |
Tableau Fundamentals for the Certificate
The certificate uses Tableau Public (the free version). You need to know how to connect to data, create basic charts by dragging dimensions and measures to rows/columns, apply filters, create calculated fields, build dashboards by combining multiple charts, and add tooltips and captions.
You don't need to know advanced Tableau features like LOD expressions or complex table calculations for the certificate.
Data Storytelling Principles
The certificate places heavy emphasis on presenting your findings to stakeholders, not just creating charts. Key principles: lead with the insight, not the methodology; use titles that tell the story (not just label the data); eliminate chart junk; maintain consistent color usage; and tailor your level of detail to your audience's technical literacy.
A chart that requires explanation is a chart that needs redesign. The best data visualizations are self-evident.