Stats 1.5Concept6 parts

Box Plots and Violin Plots

Compare the distributions of several groups side by side.

In this lesson6 parts

  1. 01Construct four comparable recorded groups
  2. 02Derive one box from ordered Midtown trips
  3. 03Calculate whiskers and flagged observations
  4. 04Compare the four boxes on one minute scale
  5. 05Build a violin from the same trips
  6. 06Interpret, reproduce and challenge

Key terms

The words this lesson introduces, each in one line. The module’s glossary collects them all.

box plot
A plot of quartiles, median, whiskers and flagged observations.
Tukey fence
Q1 - 1.5 × IQR or Q3 + 1.5 × IQR.
whisker
A line from a box edge to the most extreme observed value within the fence.
flagged observation
An observed value outside a declared box-plot fence. It is a flag for inspection, not a proven error.
violin plot
A mirrored estimated density for each group, often with summary marks inside.
density normalization
The rule mapping estimated density to plotted width. With a separate scale per group, widths do not show group size.

Quiz 5 questions

Your first pick on each question is the one that counts, and a right one earns a coin. Getting one wrong here is how the lesson sticks.

Practice

Problems to solve in your own notebook. Each states the problem, not the steps: working out the steps is the exercise. Level A applies the lesson, B combines it with earlier ones, C stretches it.

The self-checking notebook for this lesson is Box plots and violin plots.

Common mistakes

What you will see when it goes wrong, why it happens, and the fix.

Where it’s used

Where this lesson’s ideas turn up in real work.