Module 06 Summary

What this module established

Identical means routinely describe completely different populations, and a bar chart of means cannot show the difference. Check the distribution before charting a summary of it.

Carry forward

• Bin width is a modelling choice. Try several, and if the conclusion changes between them, say which you chose and why.
• Box plots compare level and spread across many groups and hide shape. Overlay points when shape matters.
• An error bar shows the uncertainty of the mean, not the spread of the data. Readers routinely confuse the two.

Before moving on

Move on when every category carries a sample size or an interval, and you have identified what rests on your smallest group.

Mark complete