Everything else is ready: study the parts, the key terms and the quiz below.
Scatter, Joint and Density Plots
See a relationship between two numerical variables, including patterns a single correlation coefficient misses.
In this lesson6 parts
- 01Pair two values from each trip
- 02Build and read the scatter plot
- 03Compute association and inspect what it misses
- 04Make concentration visible with joint and marginal views
- 05Check subgroups and the interpretation limit
- 06Reproduce the plots and try another subgroup
Key terms
The words this lesson introduces, each in one line. The module’s glossary collects them all.
- scatter plot
- One point per paired observation on two numerical axes.
- overplotting
- Multiple observations cover the same plotted area.
- Pearson correlation
- The strength and direction of linear association in paired numerical values.
- hexagonal bin
- An equal-area cell that counts paired observations in a two-variable plot.
- density
- Observation concentration per unit area under a stated binning or smoothing rule.
- joint distribution
- How two variables occur together in paired observations.
- marginal distribution
- One variable's distribution after counting across the other variable.
- subgroup
- Records selected by a stated field value.
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 Scatter, joint and density 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.