Figure components

2025-02-04

Rick Gilmore

Prelude

Rutter (2009)

Overview

In the news

“State of the nation project” (n.d.)

“State of the nation project” (n.d.)

Announcements

• No deadlines this week
• Please complete your classmates’ surveys:

Last time…

Making data & Figure types

Let’s peek at your surveys

• Link to survey URLs

Considerations when making

• Nominal/discrete
  • Which categories
  • Order
  • Other?
• Ordinal

More considerations

• Continuous
  • Continuous or grouped?
• Free response

Today

• More on figure types
  • Ordinal data
  • Continuous data
• Components of data figures

More on figure types

More nominal types…

Pie charts

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#ring-chart

Ring charts

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#ring-chart

Mosaic chart

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorial-making-data.html#mosaic-plot

Pie, ring, mosaic chart mappings

• Heights & widths \(\rightarrow\) counts (or proportions)
• Areas \(\rightarrow\) counts (or proportions)

Ordinal data

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#bar-plot-ordinal

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#fig-ordinal-barplot-stacked

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#bar-plot-ordinal-stacked-alternative

Your turn

• What elements of the data are mapped to which components of the figure?
• What are the advantages and disadvantages of having so many choices of figures?

Continuous data

• Cover story
  • People who vary in age and body temperature

A cautionary tale

“The Datasaurus dozen - same stats, different graphs | Autodesk Research” (n.d.); Matejka & Fitzmaurice (2017)

Scatterplot

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#scatterplot

Histogram

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#histograms

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#histograms

Boxplot

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#boxplot

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#boxplot

Boxplot features

• Summary stats only, no raw data
• Median, upper/lower quartiles, minimum, maximum

Boxplot limitations

“The Datasaurus dozen - same stats, different graphs | Autodesk Research” (n.d.); Matejka & Fitzmaurice (2017)

Violin plots

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#violin-plots

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#scatterplot

Violin + Boxplot

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#violin-boxplot

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#violin-boxplot

Violin + Boxplot + Scatter

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#violin-boxplot-scatter

https://psu-psychology.github.io/psych-490-data-viz-2025-spring/tutorials/tutorial-making-data.html#violin-boxplot-scatter

Your turn

Critiquing figures

• Which of these is most, least informative?
• What prior knowledge do viewers need to understand the figures?

Components of data figures

Components

• Axes
  • Scales (discrete/nominal) vs. continuous
• Mappings
  • Counts \(\rightarrow\) height, length or area; color; texture
    • Sort order \(\rightarrow\) relative position
  • Values \(\rightarrow\) position
• Legends
• Caption & titles

Main points

• Multiple ways to visualize the same data
  • Raw data
  • Summaries/statistics
• What choices make the figures more vs. less readable?

Next time

From stimulus to sensation

Resources

References

Matejka, J., & Fitzmaurice, G. (2017). Same stats, different graphs: Generating datasets with varied appearance and identical statistics through simulated annealing. In Proceedings of the 2017 CHI conference on human factors in computing systems. New York, NY, USA: ACM. https://doi.org/10.1145/3025453.3025912

Rutter, S. (2009). Figure eight schoolhouse rock. Youtube. Retrieved from https://www.youtube.com/watch?v=UCGNUo-XQJ8

State of the nation project. (n.d.). Retrieved February 4, 2025, from https://stateofnation.org/

The Datasaurus dozen - same stats, different graphs | Autodesk Research. (n.d.). Retrieved June 2, 2019, from https://www.autodeskresearch.com/publications/samestats