Module 07 Summary

What this module established

Every ggplot is data, mapping and layer. You are not choosing a chart type from a menu — you are saying which column controls which visual property, and the geom follows from that.

Carry forward

• Facets, scales and labels change what a chart means. Only the theme is cosmetic, which is why theming before the mapping is right is wasted effort.
• Pick the geom from the question. A bar chart of a mean hides the spread, and two groups with the same total can behave very differently.
• A title that states the finding does more work than one that names the topic, because the chart will be read alone.
• Bar charts start at zero. A truncated axis can draw a 6% difference as a 4-to-1 one without a single false number.

Before moving on

Move on when your chart can be understood with no surrounding text and was exported by code.

Mark complete