Common chart types and when to use them
- Line charts: changes over time, such as monthly traffic.
- Bar charts: comparisons between categories, such as leads by channel.
- Stacked bars or pie charts: shares of a whole, used sparingly.
- Scatter plots: the relationship between two measures.
- Maps: data by location.
- Tables: when exact numbers matter.
Principles of good data visualization
- Start from the question the chart should answer.
- Choose the simplest chart that shows the point.
- Start bar chart axes at zero, and label axes and units clearly.
- Use color to highlight what matters, not to decorate.
- Put the takeaway in the title, such as “Organic leads doubled since March”.
Tools
Looker Studio (free, and connects to Google Analytics and Search Console), Power BI, Tableau, and the charts in Excel and Google Sheets.
Data visualization example
A monthly report lists 14 numbers in a table. The marketing manager replaces it with one line chart of leads by month, split into organic, paid and email, plus a bar chart of cost per lead by channel. In a minute the reader sees that organic leads grew while paid leads got more expensive, and the discussion moves to what to do about it.
How to design a clear marketing dashboard
- Start from the decisions the dashboard should help with.
- Show the few numbers that matter most at the top, with the change from last period.
- Use a line chart for trends, a bar chart for comparison and a table for exact values.
- Use the same colours for the same things throughout.
- Add a short sentence under each chart stating what it shows.
Data visualization mistakes
- Cutting the axis of a bar chart so small differences look large.
- Too many colours, 3D effects and decoration.
- Pie charts with many slices.
- Charts with no title, units or source.
Data visualization FAQs
Which tools can I use?
Spreadsheets, Looker Studio, Power BI and Tableau all work. Start with what your team already knows. See marketing analytics and website analytics.
How many charts should a report have?
As few as it takes to answer the question. See digital marketing KPIs.